diff --git a/include/wrapper/cef_stream_resource_handler.h b/include/wrapper/cef_stream_resource_handler.h
index 8e549ddf2..130e20b88 100644
--- a/include/wrapper/cef_stream_resource_handler.h
+++ b/include/wrapper/cef_stream_resource_handler.h
@@ -37,14 +37,10 @@
 #define CEF_INCLUDE_WRAPPER_CEF_STREAM_RESOURCE_HANDLER_H_
 #pragma once
 
-#include "include/base/cef_logging.h"
 #include "include/base/cef_macros.h"
-#include "include/base/cef_scoped_ptr.h"
-#include "include/cef_base.h"
 #include "include/cef_resource_handler.h"
 #include "include/cef_response.h"
-
-class CefStreamReader;
+#include "include/cef_stream.h"
 
 ///
 // Implementation of the CefResourceHandler class for reading from a CefStream.
@@ -65,37 +61,25 @@ class CefStreamResourceHandler : public CefResourceHandler {
                            CefResponse::HeaderMap header_map,
                            CefRefPtr<CefStreamReader> stream);
 
-  virtual ~CefStreamResourceHandler();
-
   // CefResourceHandler methods.
-  virtual bool ProcessRequest(CefRefPtr<CefRequest> request,
-                              CefRefPtr<CefCallback> callback) OVERRIDE;
-  virtual void GetResponseHeaders(CefRefPtr<CefResponse> response,
-                                  int64& response_length,
-                                  CefString& redirectUrl) OVERRIDE;
-  virtual bool ReadResponse(void* data_out,
-                            int bytes_to_read,
-                            int& bytes_read,
-                            CefRefPtr<CefCallback> callback) OVERRIDE;
-  virtual void Cancel() OVERRIDE;
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) OVERRIDE;
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) OVERRIDE;
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) OVERRIDE;
+  void Cancel() OVERRIDE;
 
  private:
-  void ReadOnFileThread(int bytes_to_read, CefRefPtr<CefCallback> callback);
-
   const int status_code_;
   const CefString status_text_;
   const CefString mime_type_;
   const CefResponse::HeaderMap header_map_;
   const CefRefPtr<CefStreamReader> stream_;
-  bool read_on_file_thread_;
-
-  class Buffer;
-  scoped_ptr<Buffer> buffer_;
-#if DCHECK_IS_ON()
-  // Used in debug builds to verify that |buffer_| isn't being accessed on
-  // multiple threads at the same time.
-  bool buffer_owned_by_file_thread_;
-#endif
 
   IMPLEMENT_REFCOUNTING(CefStreamResourceHandler);
   DISALLOW_COPY_AND_ASSIGN(CefStreamResourceHandler);
diff --git a/libcef/browser/net/internal_scheme_handler.cc b/libcef/browser/net/internal_scheme_handler.cc
index 43363f318..2ee0ec3b6 100644
--- a/libcef/browser/net/internal_scheme_handler.cc
+++ b/libcef/browser/net/internal_scheme_handler.cc
@@ -52,9 +52,11 @@ class RedirectHandler : public CefResourceHandler {
  public:
   explicit RedirectHandler(const GURL& url) : url_(url) {}
 
-  bool ProcessRequest(CefRefPtr<CefRequest> request,
-                      CefRefPtr<CefCallback> callback) override {
-    callback->Continue();
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    // Continue immediately.
+    handle_request = true;
     return true;
   }
 
@@ -65,10 +67,11 @@ class RedirectHandler : public CefResourceHandler {
     redirectUrl = url_.spec();
   }
 
-  bool ReadResponse(void* data_out,
-                    int bytes_to_read,
-                    int& bytes_read,
-                    CefRefPtr<CefCallback> callback) override {
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    NOTREACHED();
     return false;
   }
 
@@ -78,6 +81,7 @@ class RedirectHandler : public CefResourceHandler {
   GURL url_;
 
   IMPLEMENT_REFCOUNTING(RedirectHandler);
+  DISALLOW_COPY_AND_ASSIGN(RedirectHandler);
 };
 
 class InternalHandler : public CefResourceHandler {
@@ -87,9 +91,11 @@ class InternalHandler : public CefResourceHandler {
                   int size)
       : mime_type_(mime_type), reader_(reader), size_(size) {}
 
-  bool ProcessRequest(CefRefPtr<CefRequest> request,
-                      CefRefPtr<CefCallback> callback) override {
-    callback->Continue();
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    // Continue immediately.
+    handle_request = true;
     return true;
   }
 
@@ -102,11 +108,21 @@ class InternalHandler : public CefResourceHandler {
     response->SetStatus(200);
   }
 
-  bool ReadResponse(void* data_out,
-                    int bytes_to_read,
-                    int& bytes_read,
-                    CefRefPtr<CefCallback> callback) override {
-    bytes_read = reader_->Read(data_out, 1, bytes_to_read);
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    // Read until the buffer is full or until Read() returns 0 to indicate no
+    // more data.
+    bytes_read = 0;
+    int read = 0;
+    do {
+      read = static_cast<int>(
+          reader_->Read(static_cast<char*>(data_out) + bytes_read, 1,
+                        bytes_to_read - bytes_read));
+      bytes_read += read;
+    } while (read != 0 && bytes_read < bytes_to_read);
+
     return (bytes_read > 0);
   }
 
@@ -118,6 +134,7 @@ class InternalHandler : public CefResourceHandler {
   int size_;
 
   IMPLEMENT_REFCOUNTING(InternalHandler);
+  DISALLOW_COPY_AND_ASSIGN(InternalHandler);
 };
 
 class InternalHandlerFactory : public CefSchemeHandlerFactory {
@@ -170,6 +187,7 @@ class InternalHandlerFactory : public CefSchemeHandlerFactory {
   std::unique_ptr<InternalHandlerDelegate> delegate_;
 
   IMPLEMENT_REFCOUNTING(InternalHandlerFactory);
+  DISALLOW_COPY_AND_ASSIGN(InternalHandlerFactory);
 };
 
 }  // namespace
diff --git a/libcef_dll/wrapper/cef_stream_resource_handler.cc b/libcef_dll/wrapper/cef_stream_resource_handler.cc
index 0362c705e..ad5a34faf 100644
--- a/libcef_dll/wrapper/cef_stream_resource_handler.cc
+++ b/libcef_dll/wrapper/cef_stream_resource_handler.cc
@@ -6,84 +6,19 @@
 
 #include <algorithm>
 
-#include "include/base/cef_bind.h"
 #include "include/base/cef_logging.h"
-#include "include/base/cef_macros.h"
-#include "include/cef_callback.h"
-#include "include/cef_request.h"
-#include "include/cef_stream.h"
-#include "include/wrapper/cef_closure_task.h"
+#include "include/cef_task.h"
 #include "include/wrapper/cef_helpers.h"
 
-// Class that represents a readable/writable character buffer.
-class CefStreamResourceHandler::Buffer {
- public:
-  Buffer() : size_(0), bytes_requested_(0), bytes_written_(0), bytes_read_(0) {}
-
-  void Reset(int new_size) {
-    if (size_ < new_size) {
-      size_ = new_size;
-      buffer_.reset(new char[size_]);
-      DCHECK(buffer_);
-    }
-    bytes_requested_ = new_size;
-    bytes_written_ = 0;
-    bytes_read_ = 0;
-  }
-
-  bool IsEmpty() const { return (bytes_written_ == 0); }
-
-  bool CanRead() const { return (bytes_read_ < bytes_written_); }
-
-  int WriteTo(void* data_out, int bytes_to_read) {
-    const int write_size =
-        std::min(bytes_to_read, bytes_written_ - bytes_read_);
-    if (write_size > 0) {
-      memcpy(data_out, buffer_.get() + bytes_read_, write_size);
-      bytes_read_ += write_size;
-    }
-    return write_size;
-  }
-
-  int ReadFrom(CefRefPtr<CefStreamReader> reader) {
-    // Read until the buffer is full or until Read() returns 0 to indicate no
-    // more data.
-    int bytes_read;
-    do {
-      bytes_read =
-          static_cast<int>(reader->Read(buffer_.get() + bytes_written_, 1,
-                                        bytes_requested_ - bytes_written_));
-      bytes_written_ += bytes_read;
-    } while (bytes_read != 0 && bytes_written_ < bytes_requested_);
-
-    return bytes_written_;
-  }
-
- private:
-  scoped_ptr<char[]> buffer_;
-  int size_;
-  int bytes_requested_;
-  int bytes_written_;
-  int bytes_read_;
-
-  DISALLOW_COPY_AND_ASSIGN(Buffer);
-};
-
 CefStreamResourceHandler::CefStreamResourceHandler(
     const CefString& mime_type,
     CefRefPtr<CefStreamReader> stream)
     : status_code_(200),
       status_text_("OK"),
       mime_type_(mime_type),
-      stream_(stream)
-#if DCHECK_IS_ON()
-      ,
-      buffer_owned_by_file_thread_(false)
-#endif
-{
+      stream_(stream) {
   DCHECK(!mime_type_.empty());
   DCHECK(stream_.get());
-  read_on_file_thread_ = stream_->MayBlock();
 }
 
 CefStreamResourceHandler::CefStreamResourceHandler(
@@ -96,22 +31,18 @@ CefStreamResourceHandler::CefStreamResourceHandler(
       status_text_(status_text),
       mime_type_(mime_type),
       header_map_(header_map),
-      stream_(stream)
-#if DCHECK_IS_ON()
-      ,
-      buffer_owned_by_file_thread_(false)
-#endif
-{
+      stream_(stream) {
   DCHECK(!mime_type_.empty());
   DCHECK(stream_.get());
-  read_on_file_thread_ = stream_->MayBlock();
 }
 
-CefStreamResourceHandler::~CefStreamResourceHandler() {}
+bool CefStreamResourceHandler::Open(CefRefPtr<CefRequest> request,
+                                    bool& handle_request,
+                                    CefRefPtr<CefCallback> callback) {
+  DCHECK(!CefCurrentlyOn(TID_UI) && !CefCurrentlyOn(TID_IO));
 
-bool CefStreamResourceHandler::ProcessRequest(CefRefPtr<CefRequest> request,
-                                              CefRefPtr<CefCallback> callback) {
-  callback->Continue();
+  // Continue the request immediately.
+  handle_request = true;
   return true;
 }
 
@@ -119,6 +50,8 @@ void CefStreamResourceHandler::GetResponseHeaders(
     CefRefPtr<CefResponse> response,
     int64& response_length,
     CefString& redirectUrl) {
+  CEF_REQUIRE_IO_THREAD();
+
   response->SetStatus(status_code_);
   response->SetStatusText(status_text_);
   response->SetMimeType(mime_type_);
@@ -129,70 +62,26 @@ void CefStreamResourceHandler::GetResponseHeaders(
   response_length = -1;
 }
 
-bool CefStreamResourceHandler::ReadResponse(void* data_out,
-                                            int bytes_to_read,
-                                            int& bytes_read,
-                                            CefRefPtr<CefCallback> callback) {
+bool CefStreamResourceHandler::Read(
+    void* data_out,
+    int bytes_to_read,
+    int& bytes_read,
+    CefRefPtr<CefResourceReadCallback> callback) {
+  DCHECK(!CefCurrentlyOn(TID_UI) && !CefCurrentlyOn(TID_IO));
   DCHECK_GT(bytes_to_read, 0);
 
-  if (read_on_file_thread_) {
-#if DCHECK_IS_ON()
-    DCHECK(!buffer_owned_by_file_thread_);
-#endif
-    if (buffer_ && (buffer_->CanRead() || buffer_->IsEmpty())) {
-      if (buffer_->CanRead()) {
-        // Provide data from the buffer.
-        bytes_read = buffer_->WriteTo(data_out, bytes_to_read);
-        return (bytes_read > 0);
-      } else {
-        // End of the steam.
-        bytes_read = 0;
-        return false;
-      }
-    } else {
-      // Perform another read on the file thread.
-      bytes_read = 0;
-#if DCHECK_IS_ON()
-      buffer_owned_by_file_thread_ = true;
-#endif
-      CefPostTask(TID_FILE,
-                  base::Bind(&CefStreamResourceHandler::ReadOnFileThread, this,
-                             bytes_to_read, callback));
-      return true;
-    }
-  } else {
-    // Read until the buffer is full or until Read() returns 0 to indicate no
-    // more data.
-    bytes_read = 0;
-    int read = 0;
-    do {
-      read = static_cast<int>(
-          stream_->Read(static_cast<char*>(data_out) + bytes_read, 1,
-                        bytes_to_read - bytes_read));
-      bytes_read += read;
-    } while (read != 0 && bytes_read < bytes_to_read);
+  // Read until the buffer is full or until Read() returns 0 to indicate no
+  // more data.
+  bytes_read = 0;
+  int read = 0;
+  do {
+    read = static_cast<int>(
+        stream_->Read(static_cast<char*>(data_out) + bytes_read, 1,
+                      bytes_to_read - bytes_read));
+    bytes_read += read;
+  } while (read != 0 && bytes_read < bytes_to_read);
 
-    return (bytes_read > 0);
-  }
+  return (bytes_read > 0);
 }
 
 void CefStreamResourceHandler::Cancel() {}
-
-void CefStreamResourceHandler::ReadOnFileThread(
-    int bytes_to_read,
-    CefRefPtr<CefCallback> callback) {
-  CEF_REQUIRE_FILE_THREAD();
-#if DCHECK_IS_ON()
-  DCHECK(buffer_owned_by_file_thread_);
-#endif
-
-  if (!buffer_)
-    buffer_.reset(new Buffer());
-  buffer_->Reset(bytes_to_read);
-  buffer_->ReadFrom(stream_);
-
-#if DCHECK_IS_ON()
-  buffer_owned_by_file_thread_ = false;
-#endif
-  callback->Continue();
-}
diff --git a/tests/cefclient/browser/scheme_test.cc b/tests/cefclient/browser/scheme_test.cc
index 4aab1e5e4..1e9dd12f9 100644
--- a/tests/cefclient/browser/scheme_test.cc
+++ b/tests/cefclient/browser/scheme_test.cc
@@ -28,9 +28,13 @@ class ClientSchemeHandler : public CefResourceHandler {
  public:
   ClientSchemeHandler() : offset_(0) {}
 
-  virtual bool ProcessRequest(CefRefPtr<CefRequest> request,
-                              CefRefPtr<CefCallback> callback) OVERRIDE {
-    CEF_REQUIRE_IO_THREAD();
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) OVERRIDE {
+    DCHECK(!CefCurrentlyOn(TID_UI) && !CefCurrentlyOn(TID_IO));
+
+    // The request will be continued or canceled based on the return value.
+    handle_request = true;
 
     bool handled = false;
 
@@ -70,18 +74,12 @@ class ClientSchemeHandler : public CefResourceHandler {
       }
     }
 
-    if (handled) {
-      // Indicate the headers are available.
-      callback->Continue();
-      return true;
-    }
-
-    return false;
+    return handled;
   }
 
-  virtual void GetResponseHeaders(CefRefPtr<CefResponse> response,
-                                  int64& response_length,
-                                  CefString& redirectUrl) OVERRIDE {
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) OVERRIDE {
     CEF_REQUIRE_IO_THREAD();
 
     DCHECK(!data_.empty());
@@ -93,13 +91,13 @@ class ClientSchemeHandler : public CefResourceHandler {
     response_length = data_.length();
   }
 
-  virtual void Cancel() OVERRIDE { CEF_REQUIRE_IO_THREAD(); }
+  void Cancel() OVERRIDE { CEF_REQUIRE_IO_THREAD(); }
 
-  virtual bool ReadResponse(void* data_out,
-                            int bytes_to_read,
-                            int& bytes_read,
-                            CefRefPtr<CefCallback> callback) OVERRIDE {
-    CEF_REQUIRE_IO_THREAD();
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) OVERRIDE {
+    DCHECK(!CefCurrentlyOn(TID_UI) && !CefCurrentlyOn(TID_IO));
 
     bool has_data = false;
     bytes_read = 0;
@@ -124,22 +122,25 @@ class ClientSchemeHandler : public CefResourceHandler {
   size_t offset_;
 
   IMPLEMENT_REFCOUNTING(ClientSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(ClientSchemeHandler);
 };
 
 // Implementation of the factory for for creating schema handlers.
 class ClientSchemeHandlerFactory : public CefSchemeHandlerFactory {
  public:
+  ClientSchemeHandlerFactory() {}
+
   // Return a new scheme handler instance to handle the request.
-  virtual CefRefPtr<CefResourceHandler> Create(
-      CefRefPtr<CefBrowser> browser,
-      CefRefPtr<CefFrame> frame,
-      const CefString& scheme_name,
-      CefRefPtr<CefRequest> request) OVERRIDE {
+  CefRefPtr<CefResourceHandler> Create(CefRefPtr<CefBrowser> browser,
+                                       CefRefPtr<CefFrame> frame,
+                                       const CefString& scheme_name,
+                                       CefRefPtr<CefRequest> request) OVERRIDE {
     CEF_REQUIRE_IO_THREAD();
     return new ClientSchemeHandler();
   }
 
   IMPLEMENT_REFCOUNTING(ClientSchemeHandlerFactory);
+  DISALLOW_COPY_AND_ASSIGN(ClientSchemeHandlerFactory);
 };
 
 }  // namespace
diff --git a/tests/ceftests/cookie_unittest.cc b/tests/ceftests/cookie_unittest.cc
index d7a425ae0..57f33e6a1 100644
--- a/tests/ceftests/cookie_unittest.cc
+++ b/tests/ceftests/cookie_unittest.cc
@@ -709,8 +709,11 @@ class CookieTestSchemeHandler : public TestHandler {
     explicit SchemeHandler(CookieTestSchemeHandler* handler)
         : handler_(handler), offset_(0) {}
 
-    bool ProcessRequest(CefRefPtr<CefRequest> request,
-                        CefRefPtr<CefCallback> callback) override {
+    bool Open(CefRefPtr<CefRequest> request,
+              bool& handle_request,
+              CefRefPtr<CefCallback> callback) override {
+      EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
       std::string url = request->GetURL();
       if (url == handler_->url1_) {
         content_ = "<html><body>COOKIE TEST1</body></html>";
@@ -731,7 +734,9 @@ class CookieTestSchemeHandler : public TestHandler {
         if (it != headerMap.end() && it->second == "name2=value2")
           handler_->got_process_request_cookie_.yes();
       }
-      callback->Continue();
+
+      // Continue immediately.
+      handle_request = true;
       return true;
     }
 
@@ -751,10 +756,12 @@ class CookieTestSchemeHandler : public TestHandler {
       }
     }
 
-    bool ReadResponse(void* data_out,
-                      int bytes_to_read,
-                      int& bytes_read,
-                      CefRefPtr<CefCallback> callback) override {
+    bool Read(void* data_out,
+              int bytes_to_read,
+              int& bytes_read,
+              CefRefPtr<CefResourceReadCallback> callback) override {
+      EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
       bool has_data = false;
       bytes_read = 0;
 
@@ -781,6 +788,7 @@ class CookieTestSchemeHandler : public TestHandler {
     std::string cookie_;
 
     IMPLEMENT_REFCOUNTING(SchemeHandler);
+    DISALLOW_COPY_AND_ASSIGN(SchemeHandler);
   };
 
   class SchemeHandlerFactory : public CefSchemeHandlerFactory {
@@ -810,6 +818,7 @@ class CookieTestSchemeHandler : public TestHandler {
     CookieTestSchemeHandler* handler_;
 
     IMPLEMENT_REFCOUNTING(SchemeHandlerFactory);
+    DISALLOW_COPY_AND_ASSIGN(SchemeHandlerFactory);
   };
 
   CookieTestSchemeHandler(const std::string& scheme,
@@ -1106,9 +1115,10 @@ class CookieAccessSchemeHandler : public CefResourceHandler {
   explicit CookieAccessSchemeHandler(CookieAccessData* data)
       : data_(data), offset_(0) {}
 
-  bool ProcessRequest(CefRefPtr<CefRequest> request,
-                      CefRefPtr<CefCallback> callback) override {
-    EXPECT_IO_THREAD();
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
 
     CefRequest::HeaderMap headerMap;
     request->GetHeaderMap(headerMap);
@@ -1116,7 +1126,7 @@ class CookieAccessSchemeHandler : public CefResourceHandler {
     TestCookieString(cookie_str, data_->cookie_js_ct_, data_->cookie_net_ct_);
 
     // Continue immediately.
-    callback->Continue();
+    handle_request = true;
     return true;
   }
 
@@ -1136,11 +1146,11 @@ class CookieAccessSchemeHandler : public CefResourceHandler {
     response_length = data_->response_data.length();
   }
 
-  bool ReadResponse(void* response_data_out,
-                    int bytes_to_read,
-                    int& bytes_read,
-                    CefRefPtr<CefCallback> callback) override {
-    EXPECT_IO_THREAD();
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
 
     bool has_data = false;
     bytes_read = 0;
@@ -1149,8 +1159,7 @@ class CookieAccessSchemeHandler : public CefResourceHandler {
     if (offset_ < size) {
       int transfer_size =
           std::min(bytes_to_read, static_cast<int>(size - offset_));
-      memcpy(response_data_out, data_->response_data.c_str() + offset_,
-             transfer_size);
+      memcpy(data_out, data_->response_data.c_str() + offset_, transfer_size);
       offset_ += transfer_size;
 
       bytes_read = transfer_size;
@@ -1185,6 +1194,7 @@ class CookieAccessSchemeHandler : public CefResourceHandler {
   size_t offset_;
 
   IMPLEMENT_REFCOUNTING(CookieAccessSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(CookieAccessSchemeHandler);
 };
 
 class CookieAccessSchemeHandlerFactory : public CefSchemeHandlerFactory,
diff --git a/tests/ceftests/download_unittest.cc b/tests/ceftests/download_unittest.cc
index 5796fc0f2..6408f6fe3 100644
--- a/tests/ceftests/download_unittest.cc
+++ b/tests/ceftests/download_unittest.cc
@@ -22,7 +22,7 @@ const char kTestContentDisposition[] =
 const char kTestMimeType[] = "text/plain";
 const char kTestContent[] = "Download test text";
 
-typedef base::Callback<void(CefRefPtr<CefCallback> /*callback*/)> DelayCallback;
+typedef base::Callback<void(const base::Closure& /*callback*/)> DelayCallback;
 
 class DownloadSchemeHandler : public CefResourceHandler {
  public:
@@ -33,8 +33,11 @@ class DownloadSchemeHandler : public CefResourceHandler {
         should_delay_(false),
         offset_(0) {}
 
-  bool ProcessRequest(CefRefPtr<CefRequest> request,
-                      CefRefPtr<CefCallback> callback) override {
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
     std::string url = request->GetURL();
     if (url == kTestDownloadUrl) {
       got_download_request_->yes();
@@ -44,10 +47,14 @@ class DownloadSchemeHandler : public CefResourceHandler {
       should_delay_ = true;
     } else {
       EXPECT_TRUE(false);  // Not reached.
+
+      // Cancel immediately.
+      handle_request = true;
       return false;
     }
 
-    callback->Continue();
+    // Continue immediately.
+    handle_request = true;
     return true;
   }
 
@@ -68,19 +75,37 @@ class DownloadSchemeHandler : public CefResourceHandler {
     }
   }
 
-  bool ReadResponse(void* data_out,
-                    int bytes_to_read,
-                    int& bytes_read,
-                    CefRefPtr<CefCallback> callback) override {
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
     bytes_read = 0;
 
     if (should_delay_ && !delay_callback_.is_null()) {
       // Delay the download response a single time.
-      delay_callback_.Run(callback);
+      delay_callback_.Run(base::Bind(&DownloadSchemeHandler::ContinueRead, this,
+                                     data_out, bytes_to_read, callback));
       delay_callback_.Reset();
       return true;
     }
 
+    return DoRead(data_out, bytes_to_read, bytes_read);
+  }
+
+  void Cancel() override {}
+
+ private:
+  void ContinueRead(void* data_out,
+                    int bytes_to_read,
+                    CefRefPtr<CefResourceReadCallback> callback) {
+    int bytes_read = 0;
+    DoRead(data_out, bytes_to_read, bytes_read);
+    callback->Continue(bytes_read);
+  }
+
+  bool DoRead(void* data_out, int bytes_to_read, int& bytes_read) {
     bool has_data = false;
     size_t size = content_.size();
     if (offset_ < size) {
@@ -96,9 +121,6 @@ class DownloadSchemeHandler : public CefResourceHandler {
     return has_data;
   }
 
-  void Cancel() override {}
-
- private:
   DelayCallback delay_callback_;
   TrackCallback* got_download_request_;
   bool should_delay_;
@@ -106,8 +128,10 @@ class DownloadSchemeHandler : public CefResourceHandler {
   std::string mime_type_;
   std::string content_disposition_;
   size_t offset_;
+  CefRefPtr<CefResourceReadCallback> read_callback_;
 
   IMPLEMENT_REFCOUNTING(DownloadSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(DownloadSchemeHandler);
 };
 
 class DownloadSchemeHandlerFactory : public CefSchemeHandlerFactory {
@@ -129,6 +153,7 @@ class DownloadSchemeHandlerFactory : public CefSchemeHandlerFactory {
   TrackCallback* got_download_request_;
 
   IMPLEMENT_REFCOUNTING(DownloadSchemeHandlerFactory);
+  DISALLOW_COPY_AND_ASSIGN(DownloadSchemeHandlerFactory);
 };
 
 class DownloadTestHandler : public TestHandler {
@@ -239,7 +264,7 @@ class DownloadTestHandler : public TestHandler {
   }
 
   // Callback from the scheme handler when the download request is delayed.
-  void OnDelayCallback(CefRefPtr<CefCallback> callback) {
+  void OnDelayCallback(const base::Closure& callback) {
     if (!CefCurrentlyOn(TID_UI)) {
       CefPostTask(TID_UI, base::Bind(&DownloadTestHandler::OnDelayCallback,
                                      this, callback));
@@ -261,8 +286,9 @@ class DownloadTestHandler : public TestHandler {
   void ContinueNavigatedIfReady() {
     EXPECT_EQ(test_mode_, NAVIGATED);
     if (got_delay_callback_ && got_nav_load_) {
-      delay_callback_->Continue();
-      delay_callback_ = nullptr;
+      EXPECT_FALSE(delay_callback_.is_null());
+      delay_callback_.Run();
+      delay_callback_.Reset();
     }
   }
 
@@ -462,7 +488,7 @@ class DownloadTestHandler : public TestHandler {
   CefRefPtr<CefRequestContext> request_context_;
 
   // Used with NAVIGATED and PENDING test modes.
-  CefRefPtr<CefCallback> delay_callback_;
+  base::Closure delay_callback_;
 
   // Used with PENDING test mode.
   CefRefPtr<CefDownloadItemCallback> download_item_callback_;
diff --git a/tests/ceftests/navigation_unittest.cc b/tests/ceftests/navigation_unittest.cc
index 36f9b371f..1a09c0c8f 100644
--- a/tests/ceftests/navigation_unittest.cc
+++ b/tests/ceftests/navigation_unittest.cc
@@ -688,9 +688,10 @@ class RedirectSchemeHandler : public CefResourceHandler {
  public:
   RedirectSchemeHandler() : offset_(0), status_(0) {}
 
-  bool ProcessRequest(CefRefPtr<CefRequest> request,
-                      CefRefPtr<CefCallback> callback) override {
-    EXPECT_TRUE(CefCurrentlyOn(TID_IO));
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
 
     std::string url = request->GetURL();
     if (url == kRNav1) {
@@ -711,13 +712,16 @@ class RedirectSchemeHandler : public CefResourceHandler {
       content_ = "<html><body>Nav4</body></html>";
     }
 
+    handle_request = true;
+
     if (status_ != 0) {
-      callback->Continue();
+      // Continue request.
       return true;
-    } else {
-      g_got_invalid_request = true;
-      return false;
     }
+
+    // Cancel request.
+    g_got_invalid_request = true;
+    return false;
   }
 
   void GetResponseHeaders(CefRefPtr<CefResponse> response,
@@ -748,11 +752,14 @@ class RedirectSchemeHandler : public CefResourceHandler {
 
   void Cancel() override { EXPECT_TRUE(CefCurrentlyOn(TID_IO)); }
 
-  bool ReadResponse(void* data_out,
-                    int bytes_to_read,
-                    int& bytes_read,
-                    CefRefPtr<CefCallback> callback) override {
-    EXPECT_TRUE(CefCurrentlyOn(TID_IO));
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    bytes_read = 0;
+    bool has_data = false;
 
     size_t size = content_.size();
     if (offset_ < size) {
@@ -762,10 +769,10 @@ class RedirectSchemeHandler : public CefResourceHandler {
       offset_ += transfer_size;
 
       bytes_read = transfer_size;
-      return true;
+      has_data = true;
     }
 
-    return false;
+    return has_data;
   }
 
  protected:
@@ -775,6 +782,7 @@ class RedirectSchemeHandler : public CefResourceHandler {
   std::string location_;
 
   IMPLEMENT_REFCOUNTING(RedirectSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(RedirectSchemeHandler);
 };
 
 class RedirectSchemeHandlerFactory : public CefSchemeHandlerFactory {
@@ -795,6 +803,7 @@ class RedirectSchemeHandlerFactory : public CefSchemeHandlerFactory {
   }
 
   IMPLEMENT_REFCOUNTING(RedirectSchemeHandlerFactory);
+  DISALLOW_COPY_AND_ASSIGN(RedirectSchemeHandlerFactory);
 };
 
 class RedirectTestHandler : public TestHandler {
@@ -2843,9 +2852,13 @@ class UnstartedSchemeHandler : public CefResourceHandler {
  public:
   UnstartedSchemeHandler() {}
 
-  bool ProcessRequest(CefRefPtr<CefRequest> request,
-                      CefRefPtr<CefCallback> callback) override {
-    callback->Continue();
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    // Continue immediately.
+    handle_request = true;
     return true;
   }
 
@@ -2859,10 +2872,12 @@ class UnstartedSchemeHandler : public CefResourceHandler {
 
   void Cancel() override { callback_ = nullptr; }
 
-  bool ReadResponse(void* data_out,
-                    int bytes_to_read,
-                    int& bytes_read,
-                    CefRefPtr<CefCallback> callback) override {
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
     callback_ = callback;
 
     // Pretend that we'll provide the data later.
@@ -2871,9 +2886,10 @@ class UnstartedSchemeHandler : public CefResourceHandler {
   }
 
  protected:
-  CefRefPtr<CefCallback> callback_;
+  CefRefPtr<CefResourceReadCallback> callback_;
 
   IMPLEMENT_REFCOUNTING(UnstartedSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(UnstartedSchemeHandler);
 };
 
 // Browser side.
@@ -3055,9 +3071,13 @@ class StalledSchemeHandler : public CefResourceHandler {
  public:
   StalledSchemeHandler() : offset_(0), write_size_(0) {}
 
-  bool ProcessRequest(CefRefPtr<CefRequest> request,
-                      CefRefPtr<CefCallback> callback) override {
-    callback->Continue();
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    // Continue immediately.
+    handle_request = true;
     return true;
   }
 
@@ -3074,18 +3094,23 @@ class StalledSchemeHandler : public CefResourceHandler {
 
   void Cancel() override { callback_ = nullptr; }
 
-  bool ReadResponse(void* data_out,
-                    int bytes_to_read,
-                    int& bytes_read,
-                    CefRefPtr<CefCallback> callback) override {
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    bytes_read = 0;
+
     size_t size = content_.size();
     if (offset_ >= write_size_) {
       // Now stall.
-      bytes_read = 0;
       callback_ = callback;
       return true;
     }
 
+    bool has_data = false;
+
     if (offset_ < size) {
       // Write up to |write_size_| bytes.
       int transfer_size =
@@ -3095,19 +3120,20 @@ class StalledSchemeHandler : public CefResourceHandler {
       offset_ += transfer_size;
 
       bytes_read = transfer_size;
-      return true;
+      has_data = true;
     }
 
-    return false;
+    return has_data;
   }
 
  protected:
   std::string content_;
   size_t offset_;
   size_t write_size_;
-  CefRefPtr<CefCallback> callback_;
+  CefRefPtr<CefResourceReadCallback> callback_;
 
   IMPLEMENT_REFCOUNTING(StalledSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(StalledSchemeHandler);
 };
 
 // Browser side.
diff --git a/tests/ceftests/resource_request_handler_unittest.cc b/tests/ceftests/resource_request_handler_unittest.cc
index ceba5904e..9f21bde17 100644
--- a/tests/ceftests/resource_request_handler_unittest.cc
+++ b/tests/ceftests/resource_request_handler_unittest.cc
@@ -22,6 +22,7 @@ namespace {
 
 // Normal stream resource handler implementation that additionally verifies
 // calls to Cancel.
+// This also tests the CefStreamResourceHandler implementation.
 class NormalResourceHandler : public CefStreamResourceHandler {
  public:
   NormalResourceHandler(int status_code,
@@ -50,27 +51,186 @@ class NormalResourceHandler : public CefStreamResourceHandler {
  private:
   const base::Closure destroy_callback_;
   int cancel_ct_ = 0;
+};
 
-  DISALLOW_COPY_AND_ASSIGN(NormalResourceHandler);
+// Normal stream resource handler implementation that additionally continues
+// using the callback object and verifies calls to Cancel.
+class CallbackResourceHandler : public CefResourceHandler {
+ public:
+  enum Mode {
+    DELAYED_OPEN,
+    DELAYED_READ,
+    IMMEDIATE_OPEN,
+    IMMEDIATE_READ,
+    DELAYED_ALL,
+    IMMEDIATE_ALL,
+  };
+
+  bool IsDelayedOpen() const {
+    return mode_ == DELAYED_OPEN || mode_ == DELAYED_ALL;
+  }
+
+  bool IsDelayedRead() const {
+    return mode_ == DELAYED_READ || mode_ == DELAYED_ALL;
+  }
+
+  bool IsImmediateOpen() const {
+    return mode_ == IMMEDIATE_OPEN || mode_ == IMMEDIATE_ALL;
+  }
+
+  bool IsImmediateRead() const {
+    return mode_ == IMMEDIATE_READ || mode_ == IMMEDIATE_ALL;
+  }
+
+  CallbackResourceHandler(Mode mode,
+                          int status_code,
+                          const CefString& status_text,
+                          const CefString& mime_type,
+                          CefResponse::HeaderMap header_map,
+                          CefRefPtr<CefStreamReader> stream,
+                          const base::Closure& destroy_callback)
+      : mode_(mode),
+        status_code_(status_code),
+        status_text_(status_text),
+        mime_type_(mime_type),
+        header_map_(header_map),
+        stream_(stream),
+        destroy_callback_(destroy_callback) {
+    DCHECK(!mime_type_.empty());
+    DCHECK(stream_.get());
+  }
+
+  ~CallbackResourceHandler() override {
+    EXPECT_EQ(1, cancel_ct_);
+    destroy_callback_.Run();
+  }
+
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    if (IsDelayedOpen()) {
+      // Continue the request asynchronously by executing the callback.
+      CefPostTask(TID_FILE_USER_VISIBLE,
+                  base::Bind(&CefCallback::Continue, callback));
+      handle_request = false;
+      return true;
+    } else if (IsImmediateOpen()) {
+      // Continue the request immediately be executing the callback.
+      callback->Continue();
+      handle_request = false;
+      return true;
+    }
+
+    // Continue the request immediately in the default manner.
+    handle_request = true;
+    return true;
+  }
+
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) override {
+    response->SetStatus(status_code_);
+    response->SetStatusText(status_text_);
+    response->SetMimeType(mime_type_);
+
+    if (!header_map_.empty())
+      response->SetHeaderMap(header_map_);
+
+    response_length = -1;
+  }
+
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+    EXPECT_GT(bytes_to_read, 0);
+
+    bytes_read = 0;
+
+    if (IsDelayedRead()) {
+      // Continue the request asynchronously by executing the callback.
+      CefPostTask(TID_FILE_USER_VISIBLE,
+                  base::Bind(&CallbackResourceHandler::ContinueRead, this,
+                             data_out, bytes_to_read, callback));
+      return true;
+    } else if (IsImmediateRead()) {
+      // Continue the request immediately be executing the callback.
+      ContinueRead(data_out, bytes_to_read, callback);
+      return true;
+    }
+
+    // Continue the request immediately in the default manner.
+    return DoRead(data_out, bytes_to_read, bytes_read);
+  }
+
+  void Cancel() override {
+    EXPECT_IO_THREAD();
+    cancel_ct_++;
+  }
+
+ private:
+  void ContinueRead(void* data_out,
+                    int bytes_to_read,
+                    CefRefPtr<CefResourceReadCallback> callback) {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    int bytes_read = 0;
+    DoRead(data_out, bytes_to_read, bytes_read);
+    callback->Continue(bytes_read);
+  }
+
+  bool DoRead(void* data_out, int bytes_to_read, int& bytes_read) {
+    DCHECK_GT(bytes_to_read, 0);
+
+    // Read until the buffer is full or until Read() returns 0 to indicate no
+    // more data.
+    bytes_read = 0;
+    int read = 0;
+    do {
+      read = static_cast<int>(
+          stream_->Read(static_cast<char*>(data_out) + bytes_read, 1,
+                        bytes_to_read - bytes_read));
+      bytes_read += read;
+    } while (read != 0 && bytes_read < bytes_to_read);
+
+    return (bytes_read > 0);
+  }
+
+  const Mode mode_;
+
+  const int status_code_;
+  const CefString status_text_;
+  const CefString mime_type_;
+  const CefResponse::HeaderMap header_map_;
+  const CefRefPtr<CefStreamReader> stream_;
+
+  const base::Closure destroy_callback_;
+  int cancel_ct_ = 0;
+
+  IMPLEMENT_REFCOUNTING(CallbackResourceHandler);
+  DISALLOW_COPY_AND_ASSIGN(CallbackResourceHandler);
 };
 
 // Resource handler implementation that never completes. Used to test
 // destruction handling behavior for in-progress requests.
-class IncompleteResourceHandler : public CefResourceHandler {
+class IncompleteResourceHandlerOld : public CefResourceHandler {
  public:
   enum TestMode {
     BLOCK_PROCESS_REQUEST,
     BLOCK_READ_RESPONSE,
   };
 
-  IncompleteResourceHandler(TestMode test_mode,
-                            const std::string& mime_type,
-                            const base::Closure& destroy_callback)
+  IncompleteResourceHandlerOld(TestMode test_mode,
+                               const std::string& mime_type,
+                               const base::Closure& destroy_callback)
       : test_mode_(test_mode),
         mime_type_(mime_type),
         destroy_callback_(destroy_callback) {}
 
-  ~IncompleteResourceHandler() override {
+  ~IncompleteResourceHandlerOld() override {
     EXPECT_EQ(1, process_request_ct_);
 
     EXPECT_EQ(1, cancel_ct_);
@@ -147,6 +307,119 @@ class IncompleteResourceHandler : public CefResourceHandler {
 
   CefRefPtr<CefCallback> incomplete_callback_;
 
+  IMPLEMENT_REFCOUNTING(IncompleteResourceHandlerOld);
+  DISALLOW_COPY_AND_ASSIGN(IncompleteResourceHandlerOld);
+};
+
+class IncompleteResourceHandler : public CefResourceHandler {
+ public:
+  enum TestMode {
+    BLOCK_OPEN,
+    BLOCK_READ,
+  };
+
+  IncompleteResourceHandler(TestMode test_mode,
+                            const std::string& mime_type,
+                            const base::Closure& destroy_callback)
+      : test_mode_(test_mode),
+        mime_type_(mime_type),
+        destroy_callback_(destroy_callback) {}
+
+  ~IncompleteResourceHandler() override {
+    EXPECT_EQ(1, open_ct_);
+
+    EXPECT_EQ(1, cancel_ct_);
+
+    if (test_mode_ == BLOCK_READ) {
+      EXPECT_EQ(1, get_response_headers_ct_);
+      EXPECT_EQ(1, read_ct_);
+    } else {
+      EXPECT_EQ(0, get_response_headers_ct_);
+      EXPECT_EQ(0, read_ct_);
+    }
+
+    destroy_callback_.Run();
+  }
+
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    open_ct_++;
+
+    if (test_mode_ == BLOCK_OPEN) {
+      // Never release or execute this callback.
+      incomplete_open_callback_ = callback;
+    } else {
+      // Continue immediately.
+      handle_request = true;
+    }
+    return true;
+  }
+
+  bool ProcessRequest(CefRefPtr<CefRequest> request,
+                      CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    return false;
+  }
+
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) override {
+    EXPECT_IO_THREAD();
+    EXPECT_EQ(test_mode_, BLOCK_READ);
+
+    get_response_headers_ct_++;
+
+    response->SetStatus(200);
+    response->SetStatusText("OK");
+    response->SetMimeType(mime_type_);
+    response_length = 100;
+  }
+
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+    EXPECT_EQ(test_mode_, BLOCK_READ);
+
+    read_ct_++;
+
+    // Never release or execute this callback.
+    incomplete_read_callback_ = callback;
+    bytes_read = 0;
+    return true;
+  }
+
+  bool ReadResponse(void* data_out,
+                    int bytes_to_read,
+                    int& bytes_read,
+                    CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    bytes_read = -2;
+    return false;
+  }
+
+  void Cancel() override {
+    EXPECT_IO_THREAD();
+    cancel_ct_++;
+  }
+
+ private:
+  const TestMode test_mode_;
+  const std::string mime_type_;
+  const base::Closure destroy_callback_;
+
+  int open_ct_ = 0;
+  int get_response_headers_ct_ = 0;
+  int read_ct_ = 0;
+  int cancel_ct_ = 0;
+
+  CefRefPtr<CefCallback> incomplete_open_callback_;
+  CefRefPtr<CefResourceReadCallback> incomplete_read_callback_;
+
   IMPLEMENT_REFCOUNTING(IncompleteResourceHandler);
   DISALLOW_COPY_AND_ASSIGN(IncompleteResourceHandler);
 };
@@ -175,11 +448,23 @@ class BasicResponseTest : public TestHandler {
     // Redirect the request (change the URL) in OnBeforeResourceLoad.
     REDIRECT_BEFORE_RESOURCE_LOAD,
 
+    // Return a CefResourceHandler from GetResourceHandler that continues
+    // immediately by using the callback object instead of the return value.
+    IMMEDIATE_REQUEST_HANDLER_OPEN,
+    IMMEDIATE_REQUEST_HANDLER_READ,
+    IMMEDIATE_REQUEST_HANDLER_ALL,
+
+    // Return a CefResourceHandler from GetResourceHandler that continues with
+    // a delay by using the callback object.
+    DELAYED_REQUEST_HANDLER_OPEN,
+    DELAYED_REQUEST_HANDLER_READ,
+    DELAYED_REQUEST_HANDLER_ALL,
+
     // Return a CefResourceHandler from GetResourceHandler that never completes,
     // then close the browser to verify destruction handling of in-progress
     // requests.
-    INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST,
-    INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE,
+    INCOMPLETE_REQUEST_HANDLER_OPEN,
+    INCOMPLETE_REQUEST_HANDLER_READ,
 
     // Redirect the request using a CefResourceHandler returned from
     // GetResourceHandler.
@@ -552,24 +837,7 @@ class BasicResponseTest : public TestHandler {
   }
 
   void DestroyTest() override {
-    if (mode_ == LOAD || mode_ == MODIFY_BEFORE_RESOURCE_LOAD) {
-      EXPECT_EQ(1, on_before_browse_ct_);
-      EXPECT_EQ(1, get_resource_request_handler_ct_);
-      EXPECT_EQ(1, get_cookie_access_filter_ct_);
-      EXPECT_EQ(1, on_before_resource_load_ct_);
-      EXPECT_EQ(1, get_resource_handler_ct_);
-      EXPECT_EQ(0, on_resource_redirect_ct_);
-
-      // Unhandled requests won't see a call to GetResourceResponseFilter
-      // or OnResourceResponse.
-      if (unhandled_) {
-        EXPECT_EQ(0, get_resource_response_filter_ct_);
-        EXPECT_EQ(0, on_resource_response_ct_);
-      } else {
-        EXPECT_EQ(1, get_resource_response_filter_ct_);
-        EXPECT_EQ(1, on_resource_response_ct_);
-      }
-    } else if (mode_ == RESTART_RESOURCE_RESPONSE) {
+    if (mode_ == RESTART_RESOURCE_RESPONSE) {
       EXPECT_EQ(1, on_before_browse_ct_);
       EXPECT_EQ(2, get_resource_request_handler_ct_);
       EXPECT_EQ(2, get_cookie_access_filter_ct_);
@@ -586,6 +854,23 @@ class BasicResponseTest : public TestHandler {
         EXPECT_EQ(1, get_resource_response_filter_ct_);
         EXPECT_EQ(2, on_resource_response_ct_);
       }
+    } else if (IsLoad()) {
+      EXPECT_EQ(1, on_before_browse_ct_);
+      EXPECT_EQ(1, get_resource_request_handler_ct_);
+      EXPECT_EQ(1, get_cookie_access_filter_ct_);
+      EXPECT_EQ(1, on_before_resource_load_ct_);
+      EXPECT_EQ(1, get_resource_handler_ct_);
+      EXPECT_EQ(0, on_resource_redirect_ct_);
+
+      // Unhandled requests won't see a call to GetResourceResponseFilter
+      // or OnResourceResponse.
+      if (unhandled_) {
+        EXPECT_EQ(0, get_resource_response_filter_ct_);
+        EXPECT_EQ(0, on_resource_response_ct_);
+      } else {
+        EXPECT_EQ(1, get_resource_response_filter_ct_);
+        EXPECT_EQ(1, on_resource_response_ct_);
+      }
     } else if (IsRedirect()) {
       EXPECT_EQ(2, on_before_browse_ct_);
       EXPECT_EQ(2, get_resource_request_handler_ct_);
@@ -634,7 +919,7 @@ class BasicResponseTest : public TestHandler {
 
       EXPECT_EQ(0, on_resource_redirect_ct_);
 
-      if (mode_ == INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE) {
+      if (mode_ == INCOMPLETE_REQUEST_HANDLER_READ) {
         EXPECT_EQ(1, get_resource_response_filter_ct_);
         EXPECT_EQ(1, on_resource_response_ct_);
       } else {
@@ -739,46 +1024,96 @@ class BasicResponseTest : public TestHandler {
     return base::Bind(&BasicResponseTest::MaybeDestroyTest, this, true);
   }
 
-  CefRefPtr<CefResourceHandler> GetOKResource() {
-    const std::string& body = GetResponseBody();
+  bool GetCallbackResourceHandlerMode(CallbackResourceHandler::Mode& mode) {
+    switch (mode_) {
+      case IMMEDIATE_REQUEST_HANDLER_OPEN:
+        mode = CallbackResourceHandler::IMMEDIATE_OPEN;
+        return true;
+      case IMMEDIATE_REQUEST_HANDLER_READ:
+        mode = CallbackResourceHandler::IMMEDIATE_READ;
+        return true;
+      case IMMEDIATE_REQUEST_HANDLER_ALL:
+        mode = CallbackResourceHandler::IMMEDIATE_ALL;
+        return true;
+      case DELAYED_REQUEST_HANDLER_OPEN:
+        mode = CallbackResourceHandler::DELAYED_OPEN;
+        return true;
+      case DELAYED_REQUEST_HANDLER_READ:
+        mode = CallbackResourceHandler::DELAYED_READ;
+        return true;
+      case DELAYED_REQUEST_HANDLER_ALL:
+        mode = CallbackResourceHandler::DELAYED_ALL;
+        return true;
+      default:
+        break;
+    }
+    return false;
+  }
+
+  CefRefPtr<CefResourceHandler> GetResource(int status_code,
+                                            const CefString& status_text,
+                                            const CefString& mime_type,
+                                            CefResponse::HeaderMap header_map,
+                                            const std::string& body) {
     CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(
         const_cast<char*>(body.c_str()), body.size());
 
-    return new NormalResourceHandler(200, "OK", "text/html",
-                                     CefResponse::HeaderMap(), stream,
+    CallbackResourceHandler::Mode handler_mode;
+    if (GetCallbackResourceHandlerMode(handler_mode)) {
+      return new CallbackResourceHandler(handler_mode, status_code, status_text,
+                                         mime_type, header_map, stream,
+                                         GetResourceDestroyCallback());
+    }
+
+    return new NormalResourceHandler(status_code, status_text, mime_type,
+                                     header_map, stream,
                                      GetResourceDestroyCallback());
   }
 
+  CefRefPtr<CefResourceHandler> GetOKResource() {
+    return GetResource(200, "OK", "text/html", CefResponse::HeaderMap(),
+                       GetResponseBody());
+  }
+
   CefRefPtr<CefResourceHandler> GetRedirectResource(
       const std::string& redirect_url) {
-    const std::string& body = GetRedirectBody();
-    CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(
-        const_cast<char*>(body.c_str()), body.size());
-
     CefResponse::HeaderMap headerMap;
     headerMap.insert(std::make_pair("Location", redirect_url));
 
-    return new NormalResourceHandler(307, "Temporary Redirect", "text/html",
-                                     headerMap, stream,
-                                     GetResourceDestroyCallback());
+    return GetResource(307, "Temporary Redirect", "text/html", headerMap,
+                       GetRedirectBody());
   }
 
   CefRefPtr<CefResourceHandler> GetIncompleteResource() {
+    if (TestOldResourceAPI()) {
+      return new IncompleteResourceHandlerOld(
+          mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN
+              ? IncompleteResourceHandlerOld::BLOCK_PROCESS_REQUEST
+              : IncompleteResourceHandlerOld::BLOCK_READ_RESPONSE,
+          "text/html", GetResourceDestroyCallback());
+    }
+
     return new IncompleteResourceHandler(
-        mode_ == INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST
-            ? IncompleteResourceHandler::BLOCK_PROCESS_REQUEST
-            : IncompleteResourceHandler::BLOCK_READ_RESPONSE,
+        mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN
+            ? IncompleteResourceHandler::BLOCK_OPEN
+            : IncompleteResourceHandler::BLOCK_READ,
         "text/html", GetResourceDestroyCallback());
   }
 
   bool IsLoad() const {
     return mode_ == LOAD || mode_ == MODIFY_BEFORE_RESOURCE_LOAD ||
-           mode_ == RESTART_RESOURCE_RESPONSE;
+           mode_ == RESTART_RESOURCE_RESPONSE ||
+           mode_ == IMMEDIATE_REQUEST_HANDLER_OPEN ||
+           mode_ == IMMEDIATE_REQUEST_HANDLER_READ ||
+           mode_ == IMMEDIATE_REQUEST_HANDLER_ALL ||
+           mode_ == DELAYED_REQUEST_HANDLER_OPEN ||
+           mode_ == DELAYED_REQUEST_HANDLER_READ ||
+           mode_ == DELAYED_REQUEST_HANDLER_ALL;
   }
 
   bool IsIncompleteRequestHandler() const {
-    return mode_ == INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST ||
-           mode_ == INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE;
+    return mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN ||
+           mode_ == INCOMPLETE_REQUEST_HANDLER_READ;
   }
 
   bool IsIncomplete() const {
@@ -916,7 +1251,7 @@ class BasicResponseTest : public TestHandler {
     // response.
     const bool incomplete_unhandled =
         (mode_ == INCOMPLETE_BEFORE_RESOURCE_LOAD ||
-         mode_ == INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST ||
+         mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN ||
          (IsAborted() && !custom_scheme_));
 
     if ((unhandled_ && !override_unhandled) || incomplete_unhandled) {
@@ -932,7 +1267,7 @@ class BasicResponseTest : public TestHandler {
       EXPECT_STREQ("", response->GetMimeType().ToString().c_str()) << callback;
       EXPECT_STREQ("", response->GetCharset().ToString().c_str()) << callback;
     } else {
-      if ((mode_ == INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE || IsAborted()) &&
+      if ((mode_ == INCOMPLETE_REQUEST_HANDLER_READ || IsAborted()) &&
           callback == kOnResourceLoadComplete) {
         // We got a response, but we also got aborted.
         EXPECT_EQ(ERR_ABORTED, response->GetError()) << callback;
@@ -1059,13 +1394,25 @@ class BasicResponseTest : public TestHandler {
              unhandled)
 
 // Tests only supported in handled mode.
-#define BASIC_TEST_HANDLED_MODES(name, custom)                          \
-  BASIC_TEST(name##IncompleteBeforeResourceLoad,                        \
-             INCOMPLETE_BEFORE_RESOURCE_LOAD, custom, false)            \
-  BASIC_TEST(name##IncompleteRequestHandlerProcessRequest,              \
-             INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST, custom, false) \
-  BASIC_TEST(name##IncompleteRequestHandlerReadResponse,                \
-             INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE, custom, false)
+#define BASIC_TEST_HANDLED_MODES(name, custom)                                \
+  BASIC_TEST(name##ImmediateRequestHandlerOpen,                               \
+             IMMEDIATE_REQUEST_HANDLER_OPEN, custom, false)                   \
+  BASIC_TEST(name##ImmediateRequestHandlerRead,                               \
+             IMMEDIATE_REQUEST_HANDLER_READ, custom, false)                   \
+  BASIC_TEST(name##ImmediateRequestHandlerAll, IMMEDIATE_REQUEST_HANDLER_ALL, \
+             custom, false)                                                   \
+  BASIC_TEST(name##DelayedRequestHandlerOpen, DELAYED_REQUEST_HANDLER_OPEN,   \
+             custom, false)                                                   \
+  BASIC_TEST(name##DelayedRequestHandlerRead, DELAYED_REQUEST_HANDLER_READ,   \
+             custom, false)                                                   \
+  BASIC_TEST(name##DelayedRequestHandlerAll, DELAYED_REQUEST_HANDLER_ALL,     \
+             custom, false)                                                   \
+  BASIC_TEST(name##IncompleteBeforeResourceLoad,                              \
+             INCOMPLETE_BEFORE_RESOURCE_LOAD, custom, false)                  \
+  BASIC_TEST(name##IncompleteRequestHandlerOpen,                              \
+             INCOMPLETE_REQUEST_HANDLER_OPEN, custom, false)                  \
+  BASIC_TEST(name##IncompleteRequestHandlerRead,                              \
+             INCOMPLETE_REQUEST_HANDLER_READ, custom, false)
 
 BASIC_TEST_ALL_MODES(StandardHandled, false, false)
 BASIC_TEST_ALL_MODES(StandardUnhandled, false, true)
@@ -1095,11 +1442,23 @@ class SubresourceResponseTest : public RoutingTestHandler {
     // Redirect the request (change the URL) in OnBeforeResourceLoad.
     REDIRECT_BEFORE_RESOURCE_LOAD,
 
+    // Return a CefResourceHandler from GetResourceHandler that continues
+    // immediately by using the callback object instead of the return value.
+    IMMEDIATE_REQUEST_HANDLER_OPEN,
+    IMMEDIATE_REQUEST_HANDLER_READ,
+    IMMEDIATE_REQUEST_HANDLER_ALL,
+
+    // Return a CefResourceHandler from GetResourceHandler that continues with
+    // a delay by using the callback object.
+    DELAYED_REQUEST_HANDLER_OPEN,
+    DELAYED_REQUEST_HANDLER_READ,
+    DELAYED_REQUEST_HANDLER_ALL,
+
     // Return a CefResourceHandler from GetResourceHandler that never completes,
     // then close the browser to verify destruction handling of in-progress
     // requests.
-    INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST,
-    INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE,
+    INCOMPLETE_REQUEST_HANDLER_OPEN,
+    INCOMPLETE_REQUEST_HANDLER_READ,
 
     // Redirect the request using a CefResourceHandler returned from
     // GetResourceHandler.
@@ -1581,22 +1940,7 @@ class SubresourceResponseTest : public RoutingTestHandler {
       EXPECT_EQ(1, on_before_browse_ct_);
     }
 
-    if (mode_ == LOAD || mode_ == MODIFY_BEFORE_RESOURCE_LOAD) {
-      EXPECT_EQ(1, get_resource_request_handler_ct_);
-      EXPECT_EQ(1, get_cookie_access_filter_ct_);
-      EXPECT_EQ(1, on_before_resource_load_ct_);
-      EXPECT_EQ(1, get_resource_handler_ct_);
-      EXPECT_EQ(0, on_resource_redirect_ct_);
-      // Unhandled requests won't see a call to GetResourceResponseFilter or
-      // OnResourceResponse.
-      if (unhandled_) {
-        EXPECT_EQ(0, get_resource_response_filter_ct_);
-        EXPECT_EQ(0, on_resource_response_ct_);
-      } else {
-        EXPECT_EQ(1, get_resource_response_filter_ct_);
-        EXPECT_EQ(1, on_resource_response_ct_);
-      }
-    } else if (mode_ == RESTART_RESOURCE_RESPONSE) {
+    if (mode_ == RESTART_RESOURCE_RESPONSE) {
       EXPECT_EQ(2, get_resource_request_handler_ct_);
       EXPECT_EQ(2, get_cookie_access_filter_ct_);
       EXPECT_EQ(2, on_before_resource_load_ct_);
@@ -1612,6 +1956,21 @@ class SubresourceResponseTest : public RoutingTestHandler {
         EXPECT_EQ(1, get_resource_response_filter_ct_);
         EXPECT_EQ(2, on_resource_response_ct_);
       }
+    } else if (IsLoad()) {
+      EXPECT_EQ(1, get_resource_request_handler_ct_);
+      EXPECT_EQ(1, get_cookie_access_filter_ct_);
+      EXPECT_EQ(1, on_before_resource_load_ct_);
+      EXPECT_EQ(1, get_resource_handler_ct_);
+      EXPECT_EQ(0, on_resource_redirect_ct_);
+      // Unhandled requests won't see a call to GetResourceResponseFilter or
+      // OnResourceResponse.
+      if (unhandled_) {
+        EXPECT_EQ(0, get_resource_response_filter_ct_);
+        EXPECT_EQ(0, on_resource_response_ct_);
+      } else {
+        EXPECT_EQ(1, get_resource_response_filter_ct_);
+        EXPECT_EQ(1, on_resource_response_ct_);
+      }
     } else if (IsRedirect()) {
       EXPECT_EQ(2, get_resource_request_handler_ct_);
       EXPECT_EQ(2, get_cookie_access_filter_ct_);
@@ -1655,7 +2014,7 @@ class SubresourceResponseTest : public RoutingTestHandler {
 
       EXPECT_EQ(0, on_resource_redirect_ct_);
 
-      if (mode_ == INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE) {
+      if (mode_ == INCOMPLETE_REQUEST_HANDLER_READ) {
         EXPECT_EQ(1, get_resource_response_filter_ct_);
         EXPECT_EQ(1, on_resource_response_ct_);
       } else {
@@ -1812,66 +2171,106 @@ class SubresourceResponseTest : public RoutingTestHandler {
     return base::Bind(&SubresourceResponseTest::MaybeDestroyTest, this, true);
   }
 
-  CefRefPtr<CefResourceHandler> GetMainResource() {
-    const std::string& body = GetMainResponseBody();
+  bool GetCallbackResourceHandlerMode(CallbackResourceHandler::Mode& mode) {
+    switch (mode_) {
+      case IMMEDIATE_REQUEST_HANDLER_OPEN:
+        mode = CallbackResourceHandler::IMMEDIATE_OPEN;
+        return true;
+      case IMMEDIATE_REQUEST_HANDLER_READ:
+        mode = CallbackResourceHandler::IMMEDIATE_READ;
+        return true;
+      case IMMEDIATE_REQUEST_HANDLER_ALL:
+        mode = CallbackResourceHandler::IMMEDIATE_ALL;
+        return true;
+      case DELAYED_REQUEST_HANDLER_OPEN:
+        mode = CallbackResourceHandler::DELAYED_OPEN;
+        return true;
+      case DELAYED_REQUEST_HANDLER_READ:
+        mode = CallbackResourceHandler::DELAYED_READ;
+        return true;
+      case DELAYED_REQUEST_HANDLER_ALL:
+        mode = CallbackResourceHandler::DELAYED_ALL;
+        return true;
+      default:
+        break;
+    }
+    return false;
+  }
+
+  CefRefPtr<CefResourceHandler> GetResource(int status_code,
+                                            const CefString& status_text,
+                                            const CefString& mime_type,
+                                            CefResponse::HeaderMap header_map,
+                                            const std::string& body) {
     CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(
         const_cast<char*>(body.c_str()), body.size());
 
-    return new NormalResourceHandler(200, "OK", "text/html",
-                                     CefResponse::HeaderMap(), stream,
+    CallbackResourceHandler::Mode handler_mode;
+    if (GetCallbackResourceHandlerMode(handler_mode)) {
+      return new CallbackResourceHandler(handler_mode, status_code, status_text,
+                                         mime_type, header_map, stream,
+                                         GetResourceDestroyCallback());
+    }
+
+    return new NormalResourceHandler(status_code, status_text, mime_type,
+                                     header_map, stream,
                                      GetResourceDestroyCallback());
   }
 
+  CefRefPtr<CefResourceHandler> GetMainResource() {
+    return GetResource(200, "OK", "text/html", CefResponse::HeaderMap(),
+                       GetMainResponseBody());
+  }
+
   CefRefPtr<CefResourceHandler> GetSubResource() {
-    const std::string& body = GetSubResponseBody();
-    CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(
-        const_cast<char*>(body.c_str()), body.size());
-
-    return new NormalResourceHandler(200, "OK", "text/html",
-                                     CefResponse::HeaderMap(), stream,
-                                     GetResourceDestroyCallback());
+    return GetResource(200, "OK", "text/html", CefResponse::HeaderMap(),
+                       GetSubResponseBody());
   }
 
   CefRefPtr<CefResourceHandler> GetOKResource() {
-    const std::string& body = GetResponseBody();
-    CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(
-        const_cast<char*>(body.c_str()), body.size());
-
-    return new NormalResourceHandler(200, "OK", "text/javascript",
-                                     CefResponse::HeaderMap(), stream,
-                                     GetResourceDestroyCallback());
+    return GetResource(200, "OK", "text/javascript", CefResponse::HeaderMap(),
+                       GetResponseBody());
   }
 
   CefRefPtr<CefResourceHandler> GetRedirectResource(
       const std::string& redirect_url) {
-    const std::string& body = GetRedirectBody();
-    CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(
-        const_cast<char*>(body.c_str()), body.size());
-
     CefResponse::HeaderMap headerMap;
     headerMap.insert(std::make_pair("Location", redirect_url));
 
-    return new NormalResourceHandler(307, "Temporary Redirect",
-                                     "text/javascript", headerMap, stream,
-                                     GetResourceDestroyCallback());
+    return GetResource(307, "Temporary Redirect", "text/javascript", headerMap,
+                       GetRedirectBody());
   }
 
   CefRefPtr<CefResourceHandler> GetIncompleteResource() {
+    if (TestOldResourceAPI()) {
+      return new IncompleteResourceHandlerOld(
+          mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN
+              ? IncompleteResourceHandlerOld::BLOCK_PROCESS_REQUEST
+              : IncompleteResourceHandlerOld::BLOCK_READ_RESPONSE,
+          "text/javascript", GetResourceDestroyCallback());
+    }
+
     return new IncompleteResourceHandler(
-        mode_ == INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST
-            ? IncompleteResourceHandler::BLOCK_PROCESS_REQUEST
-            : IncompleteResourceHandler::BLOCK_READ_RESPONSE,
+        mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN
+            ? IncompleteResourceHandler::BLOCK_OPEN
+            : IncompleteResourceHandler::BLOCK_READ,
         "text/javascript", GetResourceDestroyCallback());
   }
 
   bool IsLoad() const {
     return mode_ == LOAD || mode_ == MODIFY_BEFORE_RESOURCE_LOAD ||
-           mode_ == RESTART_RESOURCE_RESPONSE;
+           mode_ == RESTART_RESOURCE_RESPONSE ||
+           mode_ == IMMEDIATE_REQUEST_HANDLER_OPEN ||
+           mode_ == IMMEDIATE_REQUEST_HANDLER_READ ||
+           mode_ == IMMEDIATE_REQUEST_HANDLER_ALL ||
+           mode_ == DELAYED_REQUEST_HANDLER_OPEN ||
+           mode_ == DELAYED_REQUEST_HANDLER_READ ||
+           mode_ == DELAYED_REQUEST_HANDLER_ALL;
   }
 
   bool IsIncompleteRequestHandler() const {
-    return mode_ == INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST ||
-           mode_ == INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE;
+    return mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN ||
+           mode_ == INCOMPLETE_REQUEST_HANDLER_READ;
   }
 
   bool IsIncomplete() const {
@@ -2010,7 +2409,7 @@ class SubresourceResponseTest : public RoutingTestHandler {
     // response.
     const bool incomplete_unhandled =
         (mode_ == INCOMPLETE_BEFORE_RESOURCE_LOAD ||
-         mode_ == INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST);
+         mode_ == INCOMPLETE_REQUEST_HANDLER_OPEN);
 
     if ((unhandled_ && !override_unhandled) || incomplete_unhandled) {
       if (incomplete_unhandled) {
@@ -2025,7 +2424,7 @@ class SubresourceResponseTest : public RoutingTestHandler {
       EXPECT_STREQ("", response->GetMimeType().ToString().c_str()) << callback;
       EXPECT_STREQ("", response->GetCharset().ToString().c_str()) << callback;
     } else {
-      if (mode_ == INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE &&
+      if (mode_ == INCOMPLETE_REQUEST_HANDLER_READ &&
           callback == kOnResourceLoadComplete) {
         // We got a response, but we also got aborted.
         EXPECT_EQ(ERR_ABORTED, response->GetError()) << callback;
@@ -2156,15 +2555,25 @@ class SubresourceResponseTest : public RoutingTestHandler {
                    custom, unhandled, subframe)
 
 // Tests only supported in handled mode.
-#define SUBRESOURCE_TEST_HANDLED_MODES(name, custom, subframe)                \
-  SUBRESOURCE_TEST(name##IncompleteBeforeResourceLoad,                        \
-                   INCOMPLETE_BEFORE_RESOURCE_LOAD, custom, false, subframe)  \
-  SUBRESOURCE_TEST(name##IncompleteRequestHandlerProcessRequest,              \
-                   INCOMPLETE_REQUEST_HANDLER_PROCESS_REQUEST, custom, false, \
-                   subframe)                                                  \
-  SUBRESOURCE_TEST(name##IncompleteRequestHandlerReadResponse,                \
-                   INCOMPLETE_REQUEST_HANDLER_READ_RESPONSE, custom, false,   \
-                   subframe)
+#define SUBRESOURCE_TEST_HANDLED_MODES(name, custom, subframe)               \
+  SUBRESOURCE_TEST(name##ImmediateRequestHandlerOpen,                        \
+                   IMMEDIATE_REQUEST_HANDLER_OPEN, custom, false, subframe)  \
+  SUBRESOURCE_TEST(name##ImmediateRequestHandlerRead,                        \
+                   IMMEDIATE_REQUEST_HANDLER_READ, custom, false, subframe)  \
+  SUBRESOURCE_TEST(name##ImmediateRequestHandlerAll,                         \
+                   IMMEDIATE_REQUEST_HANDLER_ALL, custom, false, subframe)   \
+  SUBRESOURCE_TEST(name##DelayedRequestHandlerOpen,                          \
+                   DELAYED_REQUEST_HANDLER_OPEN, custom, false, subframe)    \
+  SUBRESOURCE_TEST(name##DelayedRequestHandlerRead,                          \
+                   DELAYED_REQUEST_HANDLER_READ, custom, false, subframe)    \
+  SUBRESOURCE_TEST(name##DelayedRequestHandlerAll,                           \
+                   DELAYED_REQUEST_HANDLER_ALL, custom, false, subframe)     \
+  SUBRESOURCE_TEST(name##IncompleteBeforeResourceLoad,                       \
+                   INCOMPLETE_BEFORE_RESOURCE_LOAD, custom, false, subframe) \
+  SUBRESOURCE_TEST(name##IncompleteRequestHandlerOpen,                       \
+                   INCOMPLETE_REQUEST_HANDLER_OPEN, custom, false, subframe) \
+  SUBRESOURCE_TEST(name##IncompleteRequestHandlerRead,                       \
+                   INCOMPLETE_REQUEST_HANDLER_READ, custom, false, subframe)
 
 SUBRESOURCE_TEST_ALL_MODES(StandardHandledMainFrame, false, false, false)
 SUBRESOURCE_TEST_ALL_MODES(StandardUnhandledMainFrame, false, true, false)
diff --git a/tests/ceftests/scheme_handler_unittest.cc b/tests/ceftests/scheme_handler_unittest.cc
index 0f0029cca..d14df44fa 100644
--- a/tests/ceftests/scheme_handler_unittest.cc
+++ b/tests/ceftests/scheme_handler_unittest.cc
@@ -212,9 +212,9 @@ class TestSchemeHandler : public TestHandler {
   IMPLEMENT_REFCOUNTING(TestSchemeHandler);
 };
 
-class ClientSchemeHandler : public CefResourceHandler {
+class ClientSchemeHandlerOld : public CefResourceHandler {
  public:
-  explicit ClientSchemeHandler(TestResults* tr)
+  explicit ClientSchemeHandlerOld(TestResults* tr)
       : test_results_(tr), offset_(0), is_sub_(false), has_delayed_(false) {}
 
   bool ProcessRequest(CefRefPtr<CefRequest> request,
@@ -329,10 +329,11 @@ class ClientSchemeHandler : public CefResourceHandler {
     if (test_results_->delay > 0) {
       if (!has_delayed_) {
         // Continue after a delay.
-        CefPostDelayedTask(TID_IO,
-                           base::Bind(&ClientSchemeHandler::ContinueAfterDelay,
-                                      this, callback),
-                           test_results_->delay);
+        CefPostDelayedTask(
+            TID_IO,
+            base::Bind(&ClientSchemeHandlerOld::ContinueAfterDelay, this,
+                       callback),
+            test_results_->delay);
         bytes_read = 0;
         return true;
       }
@@ -378,7 +379,206 @@ class ClientSchemeHandler : public CefResourceHandler {
   bool is_sub_;
   bool has_delayed_;
 
+  IMPLEMENT_REFCOUNTING(ClientSchemeHandlerOld);
+  DISALLOW_COPY_AND_ASSIGN(ClientSchemeHandlerOld);
+};
+
+class ClientSchemeHandler : public CefResourceHandler {
+ public:
+  explicit ClientSchemeHandler(TestResults* tr)
+      : test_results_(tr), offset_(0), is_sub_(false), has_delayed_(false) {}
+
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    bool handled = false;
+
+    std::string url = request->GetURL();
+    is_sub_ =
+        (!test_results_->sub_url.empty() && test_results_->sub_url == url);
+
+    if (is_sub_) {
+      test_results_->got_sub_request.yes();
+
+      if (!test_results_->sub_html.empty())
+        handled = true;
+    } else {
+      EXPECT_EQ(url, test_results_->url);
+
+      test_results_->got_request.yes();
+
+      if (!test_results_->html.empty())
+        handled = true;
+    }
+
+    std::string accept_language;
+    CefRequest::HeaderMap headerMap;
+    CefRequest::HeaderMap::iterator headerIter;
+    request->GetHeaderMap(headerMap);
+    headerIter = headerMap.find("Accept-Language");
+    if (headerIter != headerMap.end())
+      accept_language = headerIter->second;
+    EXPECT_TRUE(!accept_language.empty());
+
+    if (!test_results_->accept_language.empty()) {
+      // Value from CefBrowserSettings.accept_language set in
+      // PopulateBrowserSettings().
+      EXPECT_STREQ(test_results_->accept_language.data(),
+                   accept_language.data());
+    } else {
+      // CEF_SETTINGS_ACCEPT_LANGUAGE value from
+      // CefSettings.accept_language_list set in CefTestSuite::GetSettings()
+      // and expanded internally by ComputeAcceptLanguageFromPref.
+      EXPECT_STREQ("en-GB,en;q=0.9", accept_language.data());
+    }
+
+    // Continue or cancel the request immediately based on the return value.
+    handle_request = true;
+
+    if (handled) {
+      if (test_results_->delay > 0) {
+        // Continue after the delay.
+        handle_request = false;
+        CefPostDelayedTask(TID_FILE_USER_BLOCKING,
+                           base::Bind(&CefCallback::Continue, callback.get()),
+                           test_results_->delay);
+      }
+      return true;
+    } else if (test_results_->response_error_code != ERR_NONE) {
+      // Propagate the error code.
+      return true;
+    }
+
+    // Response was canceled.
+    if (g_current_handler)
+      g_current_handler->DestroyTest();
+    return false;
+  }
+
+  bool ProcessRequest(CefRefPtr<CefRequest> request,
+                      CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    return false;
+  }
+
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) override {
+    if (is_sub_) {
+      response->SetStatus(test_results_->sub_status_code);
+
+      if (!test_results_->sub_allow_origin.empty()) {
+        // Set the Access-Control-Allow-Origin header to allow cross-domain
+        // scripting.
+        CefResponse::HeaderMap headers;
+        headers.insert(std::make_pair("Access-Control-Allow-Origin",
+                                      test_results_->sub_allow_origin));
+        response->SetHeaderMap(headers);
+      }
+
+      if (!test_results_->sub_html.empty()) {
+        response->SetMimeType("text/html");
+        response_length = test_results_->sub_html.size();
+      }
+    } else if (!test_results_->redirect_url.empty()) {
+      redirectUrl = test_results_->redirect_url;
+    } else if (test_results_->response_error_code != ERR_NONE) {
+      response->SetError(test_results_->response_error_code);
+    } else {
+      response->SetStatus(test_results_->status_code);
+
+      if (!test_results_->html.empty()) {
+        response->SetMimeType("text/html");
+        response_length = test_results_->html.size();
+      }
+    }
+  }
+
+  void Cancel() override { EXPECT_TRUE(CefCurrentlyOn(TID_IO)); }
+
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    if (test_results_->delay > 0) {
+      if (!has_delayed_) {
+        // Continue after a delay.
+        CefPostDelayedTask(TID_FILE_USER_BLOCKING,
+                           base::Bind(&ClientSchemeHandler::ContinueAfterDelay,
+                                      this, data_out, bytes_to_read, callback),
+                           test_results_->delay);
+        bytes_read = 0;
+        return true;
+      }
+
+      has_delayed_ = false;
+    }
+
+    return GetData(data_out, bytes_to_read, bytes_read);
+  }
+
+  bool ReadResponse(void* data_out,
+                    int bytes_to_read,
+                    int& bytes_read,
+                    CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    bytes_read = -2;
+    return false;
+  }
+
+ private:
+  void ContinueAfterDelay(void* data_out,
+                          int bytes_to_read,
+                          CefRefPtr<CefResourceReadCallback> callback) {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    has_delayed_ = true;
+
+    int bytes_read = 0;
+    GetData(data_out, bytes_to_read, bytes_read);
+    callback->Continue(bytes_read);
+  }
+
+  bool GetData(void* data_out, int bytes_to_read, int& bytes_read) {
+    std::string* data;
+
+    if (is_sub_) {
+      test_results_->got_sub_read.yes();
+      data = &test_results_->sub_html;
+    } else {
+      test_results_->got_read.yes();
+      data = &test_results_->html;
+    }
+
+    // Default to response complete.
+    bool has_data = false;
+    bytes_read = 0;
+
+    size_t size = data->size();
+    if (offset_ < size) {
+      int transfer_size =
+          std::min(bytes_to_read, static_cast<int>(size - offset_));
+      memcpy(data_out, data->c_str() + offset_, transfer_size);
+      offset_ += transfer_size;
+
+      bytes_read = transfer_size;
+      has_data = true;
+    }
+
+    return has_data;
+  }
+
+  TestResults* test_results_;
+  size_t offset_;
+  bool is_sub_;
+  bool has_delayed_;
+
   IMPLEMENT_REFCOUNTING(ClientSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(ClientSchemeHandler);
 };
 
 class ClientSchemeHandlerFactory : public CefSchemeHandlerFactory {
@@ -390,12 +590,16 @@ class ClientSchemeHandlerFactory : public CefSchemeHandlerFactory {
                                        const CefString& scheme_name,
                                        CefRefPtr<CefRequest> request) override {
     EXPECT_TRUE(CefCurrentlyOn(TID_IO));
+    if (TestOldResourceAPI()) {
+      return new ClientSchemeHandlerOld(test_results_);
+    }
     return new ClientSchemeHandler(test_results_);
   }
 
   TestResults* test_results_;
 
   IMPLEMENT_REFCOUNTING(ClientSchemeHandlerFactory);
+  DISALLOW_COPY_AND_ASSIGN(ClientSchemeHandlerFactory);
 };
 
 // Global test results object.
diff --git a/tests/ceftests/test_util.cc b/tests/ceftests/test_util.cc
index 288c7cb7e..d8e6c9dfa 100644
--- a/tests/ceftests/test_util.cc
+++ b/tests/ceftests/test_util.cc
@@ -3,6 +3,7 @@
 // can be found in the LICENSE file.
 
 #include "tests/ceftests/test_util.h"
+#include "include/cef_command_line.h"
 #include "include/cef_request_context_handler.h"
 #include "tests/gtest/include/gtest/gtest.h"
 
@@ -266,6 +267,16 @@ void TestStringVectorEqual(const std::vector<CefString>& val1,
     EXPECT_STREQ(val1[i].ToString().c_str(), val2[i].ToString().c_str());
 }
 
+bool TestOldResourceAPI() {
+  static int state = -1;
+  if (state == -1) {
+    CefRefPtr<CefCommandLine> command_line =
+        CefCommandLine::GetGlobalCommandLine();
+    state = command_line->HasSwitch("test-old-resource-api") ? 1 : 0;
+  }
+  return state ? true : false;
+}
+
 CefRefPtr<CefRequestContext> CreateTestRequestContext(
     TestRequestContextMode mode,
     const std::string& cache_path) {
diff --git a/tests/ceftests/test_util.h b/tests/ceftests/test_util.h
index 675182e2b..7f0fe4a5a 100644
--- a/tests/ceftests/test_util.h
+++ b/tests/ceftests/test_util.h
@@ -78,6 +78,9 @@ inline bool IsTestRequestContextModeCustom(TestRequestContextMode mode) {
          mode == TEST_RC_MODE_CUSTOM_WITH_HANDLER;
 }
 
+// Returns true if the old CefResourceHandler API should be tested.
+bool TestOldResourceAPI();
+
 // Return a RequestContext object matching the specified |mode|.
 // |cache_path| may be specified for CUSTOM modes.
 // Use the RC_TEST_GROUP_BASE macro to test all valid combinations.
diff --git a/tests/ceftests/urlrequest_unittest.cc b/tests/ceftests/urlrequest_unittest.cc
index ec65f9990..bb528b84c 100644
--- a/tests/ceftests/urlrequest_unittest.cc
+++ b/tests/ceftests/urlrequest_unittest.cc
@@ -546,13 +546,13 @@ bool IsAuthorized(CefRefPtr<CefRequest> request,
 // SCHEME HANDLER BACKEND
 
 // Serves request responses.
-class RequestSchemeHandler : public CefResourceHandler {
+class RequestSchemeHandlerOld : public CefResourceHandler {
  public:
-  RequestSchemeHandler(RequestRunSettings* settings,
-                       const base::Closure& destroy_callback)
+  RequestSchemeHandlerOld(RequestRunSettings* settings,
+                          const base::Closure& destroy_callback)
       : settings_(settings), destroy_callback_(destroy_callback) {}
 
-  ~RequestSchemeHandler() override {
+  ~RequestSchemeHandlerOld() override {
     EXPECT_EQ(1, cancel_ct_);
     destroy_callback_.Run();
   }
@@ -580,7 +580,7 @@ class RequestSchemeHandler : public CefResourceHandler {
     response_length = response_data_.length();
   }
 
-  bool ReadResponse(void* response_data_out,
+  bool ReadResponse(void* data_out,
                     int bytes_to_read,
                     int& bytes_read,
                     CefRefPtr<CefCallback> callback) override {
@@ -593,8 +593,7 @@ class RequestSchemeHandler : public CefResourceHandler {
     if (offset_ < size) {
       int transfer_size =
           std::min(bytes_to_read, static_cast<int>(size - offset_));
-      memcpy(response_data_out, response_data_.c_str() + offset_,
-             transfer_size);
+      memcpy(data_out, response_data_.c_str() + offset_, transfer_size);
       offset_ += transfer_size;
 
       bytes_read = transfer_size;
@@ -609,6 +608,99 @@ class RequestSchemeHandler : public CefResourceHandler {
     cancel_ct_++;
   }
 
+ private:
+  // |settings_| is not owned by this object.
+  RequestRunSettings* settings_;
+  base::Closure destroy_callback_;
+
+  std::string response_data_;
+  size_t offset_ = 0;
+
+  int cancel_ct_ = 0;
+
+  IMPLEMENT_REFCOUNTING(RequestSchemeHandlerOld);
+  DISALLOW_COPY_AND_ASSIGN(RequestSchemeHandlerOld);
+};
+
+class RequestSchemeHandler : public CefResourceHandler {
+ public:
+  RequestSchemeHandler(RequestRunSettings* settings,
+                       const base::Closure& destroy_callback)
+      : settings_(settings), destroy_callback_(destroy_callback) {}
+
+  ~RequestSchemeHandler() override {
+    EXPECT_EQ(1, cancel_ct_);
+    destroy_callback_.Run();
+  }
+
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+    VerifyNormalRequest(settings_, request, false);
+
+    // HEAD requests are identical to GET requests except no response data is
+    // sent.
+    if (request->GetMethod() != "HEAD")
+      response_data_ = settings_->response_data;
+
+    // Continue immediately.
+    handle_request = true;
+    return true;
+  }
+
+  bool ProcessRequest(CefRefPtr<CefRequest> request,
+                      CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    return false;
+  }
+
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) override {
+    EXPECT_IO_THREAD();
+    GetNormalResponse(settings_, response);
+    response_length = response_data_.length();
+  }
+
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    // Default to response complete.
+    bool has_data = false;
+    bytes_read = 0;
+
+    size_t size = response_data_.length();
+    if (offset_ < size) {
+      int transfer_size =
+          std::min(bytes_to_read, static_cast<int>(size - offset_));
+      memcpy(data_out, response_data_.c_str() + offset_, transfer_size);
+      offset_ += transfer_size;
+
+      bytes_read = transfer_size;
+      has_data = true;
+    }
+
+    return has_data;
+  }
+
+  bool ReadResponse(void* data_out,
+                    int bytes_to_read,
+                    int& bytes_read,
+                    CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    bytes_read = -2;
+    return false;
+  }
+
+  void Cancel() override {
+    EXPECT_IO_THREAD();
+    cancel_ct_++;
+  }
+
  private:
   // |settings_| is not owned by this object.
   RequestRunSettings* settings_;
@@ -620,19 +712,20 @@ class RequestSchemeHandler : public CefResourceHandler {
   int cancel_ct_ = 0;
 
   IMPLEMENT_REFCOUNTING(RequestSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(RequestSchemeHandler);
 };
 
 // Serves redirect request responses.
-class RequestRedirectSchemeHandler : public CefResourceHandler {
+class RequestRedirectSchemeHandlerOld : public CefResourceHandler {
  public:
-  RequestRedirectSchemeHandler(CefRefPtr<CefRequest> request,
-                               CefRefPtr<CefResponse> response,
-                               const base::Closure& destroy_callback)
+  RequestRedirectSchemeHandlerOld(CefRefPtr<CefRequest> request,
+                                  CefRefPtr<CefResponse> response,
+                                  const base::Closure& destroy_callback)
       : request_(request),
         response_(response),
         destroy_callback_(destroy_callback) {}
 
-  ~RequestRedirectSchemeHandler() override {
+  ~RequestRedirectSchemeHandlerOld() override {
     EXPECT_EQ(1, cancel_ct_);
     destroy_callback_.Run();
   }
@@ -679,6 +772,89 @@ class RequestRedirectSchemeHandler : public CefResourceHandler {
     cancel_ct_++;
   }
 
+ private:
+  CefRefPtr<CefRequest> request_;
+  CefRefPtr<CefResponse> response_;
+  base::Closure destroy_callback_;
+
+  int cancel_ct_ = 0;
+
+  IMPLEMENT_REFCOUNTING(RequestRedirectSchemeHandlerOld);
+  DISALLOW_COPY_AND_ASSIGN(RequestRedirectSchemeHandlerOld);
+};
+
+class RequestRedirectSchemeHandler : public CefResourceHandler {
+ public:
+  RequestRedirectSchemeHandler(CefRefPtr<CefRequest> request,
+                               CefRefPtr<CefResponse> response,
+                               const base::Closure& destroy_callback)
+      : request_(request),
+        response_(response),
+        destroy_callback_(destroy_callback) {}
+
+  ~RequestRedirectSchemeHandler() override {
+    EXPECT_EQ(1, cancel_ct_);
+    destroy_callback_.Run();
+  }
+
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    // Verify that the request was sent correctly.
+    TestRequestEqual(request_, request, true);
+
+    // Continue immediately.
+    handle_request = true;
+    return true;
+  }
+
+  bool ProcessRequest(CefRefPtr<CefRequest> request,
+                      CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    return false;
+  }
+
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) override {
+    EXPECT_IO_THREAD();
+
+    response->SetStatus(response_->GetStatus());
+    response->SetStatusText(response_->GetStatusText());
+    response->SetMimeType(response_->GetMimeType());
+
+    CefResponse::HeaderMap headerMap;
+    response_->GetHeaderMap(headerMap);
+    response->SetHeaderMap(headerMap);
+
+    response_length = 0;
+  }
+
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    bytes_read = -1;
+    return false;
+  }
+
+  bool ReadResponse(void* data_out,
+                    int bytes_to_read,
+                    int& bytes_read,
+                    CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    bytes_read = -2;
+    return false;
+  }
+
+  void Cancel() override {
+    EXPECT_IO_THREAD();
+    cancel_ct_++;
+  }
+
  private:
   CefRefPtr<CefRequest> request_;
   CefRefPtr<CefResponse> response_;
@@ -687,19 +863,20 @@ class RequestRedirectSchemeHandler : public CefResourceHandler {
   int cancel_ct_ = 0;
 
   IMPLEMENT_REFCOUNTING(RequestRedirectSchemeHandler);
+  DISALLOW_COPY_AND_ASSIGN(RequestRedirectSchemeHandler);
 };
 
 // Resource handler implementation that never completes. Used to test
 // destruction handling behavior for in-progress requests.
-class IncompleteSchemeHandler : public CefResourceHandler {
+class IncompleteSchemeHandlerOld : public CefResourceHandler {
  public:
-  IncompleteSchemeHandler(RequestRunSettings* settings,
-                          const base::Closure& destroy_callback)
+  IncompleteSchemeHandlerOld(RequestRunSettings* settings,
+                             const base::Closure& destroy_callback)
       : settings_(settings), destroy_callback_(destroy_callback) {
     EXPECT_NE(settings_->incomplete_type, RequestRunSettings::INCOMPLETE_NONE);
   }
 
-  ~IncompleteSchemeHandler() override {
+  ~IncompleteSchemeHandlerOld() override {
     EXPECT_EQ(1, process_request_ct_);
     EXPECT_EQ(1, cancel_ct_);
 
@@ -783,6 +960,120 @@ class IncompleteSchemeHandler : public CefResourceHandler {
 
   CefRefPtr<CefCallback> incomplete_callback_;
 
+  IMPLEMENT_REFCOUNTING(IncompleteSchemeHandlerOld);
+  DISALLOW_COPY_AND_ASSIGN(IncompleteSchemeHandlerOld);
+};
+
+class IncompleteSchemeHandler : public CefResourceHandler {
+ public:
+  IncompleteSchemeHandler(RequestRunSettings* settings,
+                          const base::Closure& destroy_callback)
+      : settings_(settings), destroy_callback_(destroy_callback) {
+    EXPECT_NE(settings_->incomplete_type, RequestRunSettings::INCOMPLETE_NONE);
+  }
+
+  ~IncompleteSchemeHandler() override {
+    EXPECT_EQ(1, open_ct_);
+    EXPECT_EQ(1, cancel_ct_);
+
+    if (settings_->incomplete_type ==
+        RequestRunSettings::INCOMPLETE_READ_RESPONSE) {
+      EXPECT_EQ(1, get_response_headers_ct_);
+      EXPECT_EQ(1, read_ct_);
+    } else {
+      EXPECT_EQ(0, get_response_headers_ct_);
+      EXPECT_EQ(0, read_ct_);
+    }
+
+    destroy_callback_.Run();
+  }
+
+  bool Open(CefRefPtr<CefRequest> request,
+            bool& handle_request,
+            CefRefPtr<CefCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+
+    open_ct_++;
+
+    if (settings_->incomplete_type ==
+        RequestRunSettings::INCOMPLETE_PROCESS_REQUEST) {
+      // Never release or execute this callback.
+      incomplete_open_callback_ = callback;
+    } else {
+      // Continue immediately.
+      handle_request = true;
+    }
+    return true;
+  }
+
+  bool ProcessRequest(CefRefPtr<CefRequest> request,
+                      CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    return false;
+  }
+
+  void GetResponseHeaders(CefRefPtr<CefResponse> response,
+                          int64& response_length,
+                          CefString& redirectUrl) override {
+    EXPECT_IO_THREAD();
+    EXPECT_EQ(settings_->incomplete_type,
+              RequestRunSettings::INCOMPLETE_READ_RESPONSE);
+
+    get_response_headers_ct_++;
+
+    response->SetStatus(settings_->response->GetStatus());
+    response->SetStatusText(settings_->response->GetStatusText());
+    response->SetMimeType(settings_->response->GetMimeType());
+
+    CefResponse::HeaderMap headerMap;
+    settings_->response->GetHeaderMap(headerMap);
+    settings_->response->SetHeaderMap(headerMap);
+
+    response_length = static_cast<int64>(settings_->response_data.size());
+  }
+
+  bool Read(void* data_out,
+            int bytes_to_read,
+            int& bytes_read,
+            CefRefPtr<CefResourceReadCallback> callback) override {
+    EXPECT_FALSE(CefCurrentlyOn(TID_UI) || CefCurrentlyOn(TID_IO));
+    EXPECT_EQ(settings_->incomplete_type,
+              RequestRunSettings::INCOMPLETE_READ_RESPONSE);
+
+    read_ct_++;
+
+    // Never release or execute this callback.
+    incomplete_read_callback_ = callback;
+    bytes_read = 0;
+    return true;
+  }
+
+  bool ReadResponse(void* data_out,
+                    int bytes_to_read,
+                    int& bytes_read,
+                    CefRefPtr<CefCallback> callback) override {
+    EXPECT_TRUE(false);  // Not reached.
+    bytes_read = -2;
+    return false;
+  }
+
+  void Cancel() override {
+    EXPECT_IO_THREAD();
+    cancel_ct_++;
+  }
+
+ private:
+  RequestRunSettings* const settings_;
+  const base::Closure destroy_callback_;
+
+  int open_ct_ = 0;
+  int get_response_headers_ct_ = 0;
+  int read_ct_ = 0;
+  int cancel_ct_ = 0;
+
+  CefRefPtr<CefCallback> incomplete_open_callback_;
+  CefRefPtr<CefResourceReadCallback> incomplete_read_callback_;
+
   IMPLEMENT_REFCOUNTING(IncompleteSchemeHandler);
   DISALLOW_COPY_AND_ASSIGN(IncompleteSchemeHandler);
 };
@@ -805,10 +1096,21 @@ class RequestSchemeHandlerFactory : public CefSchemeHandlerFactory {
     if (entry.type == RequestDataMap::Entry::TYPE_NORMAL) {
       if (entry.settings->incomplete_type ==
           RequestRunSettings::INCOMPLETE_NONE) {
+        if (TestOldResourceAPI()) {
+          return new RequestSchemeHandlerOld(entry.settings, destroy_callback);
+        }
         return new RequestSchemeHandler(entry.settings, destroy_callback);
       }
+
+      if (TestOldResourceAPI()) {
+        return new IncompleteSchemeHandlerOld(entry.settings, destroy_callback);
+      }
       return new IncompleteSchemeHandler(entry.settings, destroy_callback);
     } else if (entry.type == RequestDataMap::Entry::TYPE_REDIRECT) {
+      if (TestOldResourceAPI()) {
+        return new RequestRedirectSchemeHandlerOld(
+            entry.redirect_request, entry.redirect_response, destroy_callback);
+      }
       return new RequestRedirectSchemeHandler(
           entry.redirect_request, entry.redirect_response, destroy_callback);
     }
@@ -882,6 +1184,7 @@ class RequestSchemeHandlerFactory : public CefSchemeHandlerFactory {
   base::Closure shutdown_callback_;
 
   IMPLEMENT_REFCOUNTING(RequestSchemeHandlerFactory);
+  DISALLOW_COPY_AND_ASSIGN(RequestSchemeHandlerFactory);
 };
 
 // SERVER BACKEND