Add support for loading extensions (issue #1947)

- Add CefRequestContext::LoadExtension, CefExtension, CefExtensionHandler and
  related methods/interfaces.
- Add chrome://extensions-support that lists supported Chrome APIs.
- Add CefBrowserHost::SetAutoResizeEnabled and CefDisplayHandler::OnAutoResize
  to support browser resize based on preferred web contents size.
- views: Add support for custom CefMenuButton popups.
- cefclient: Run with `--load-extension=set_page_color` command-line flag for
  an extension loading example. Add `--use-views` on Windows and Linux for an
  even better example.

libcef_dll/ctocpp/extension_ctocpp.cc

@@ -0,0 +1,163 @@
+// Copyright (c) 2017 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool. If making changes by
+// hand only do so within the body of existing method and function
+// implementations. See the translator.README.txt file in the tools directory
+// for more information.
+//
+// $hash=03f1fdb03fe9164e965e62d3e703d1b5a548ffdd$
+//
+
+#include "libcef_dll/ctocpp/extension_ctocpp.h"
+#include "libcef_dll/cpptoc/extension_handler_cpptoc.h"
+#include "libcef_dll/ctocpp/dictionary_value_ctocpp.h"
+#include "libcef_dll/ctocpp/request_context_ctocpp.h"
+
+// VIRTUAL METHODS - Body may be edited by hand.
+
+CefString CefExtensionCToCpp::GetIdentifier() {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, get_identifier))
+    return CefString();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  cef_string_userfree_t _retval = _struct->get_identifier(_struct);
+
+  // Return type: string
+  CefString _retvalStr;
+  _retvalStr.AttachToUserFree(_retval);
+  return _retvalStr;
+}
+
+CefString CefExtensionCToCpp::GetPath() {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, get_path))
+    return CefString();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  cef_string_userfree_t _retval = _struct->get_path(_struct);
+
+  // Return type: string
+  CefString _retvalStr;
+  _retvalStr.AttachToUserFree(_retval);
+  return _retvalStr;
+}
+
+CefRefPtr<CefDictionaryValue> CefExtensionCToCpp::GetManifest() {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, get_manifest))
+    return NULL;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  cef_dictionary_value_t* _retval = _struct->get_manifest(_struct);
+
+  // Return type: refptr_same
+  return CefDictionaryValueCToCpp::Wrap(_retval);
+}
+
+bool CefExtensionCToCpp::IsSame(CefRefPtr<CefExtension> that) {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, is_same))
+    return false;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: that; type: refptr_same
+  DCHECK(that.get());
+  if (!that.get())
+    return false;
+
+  // Execute
+  int _retval = _struct->is_same(_struct, CefExtensionCToCpp::Unwrap(that));
+
+  // Return type: bool
+  return _retval ? true : false;
+}
+
+CefRefPtr<CefExtensionHandler> CefExtensionCToCpp::GetHandler() {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, get_handler))
+    return NULL;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  cef_extension_handler_t* _retval = _struct->get_handler(_struct);
+
+  // Return type: refptr_diff
+  return CefExtensionHandlerCppToC::Unwrap(_retval);
+}
+
+CefRefPtr<CefRequestContext> CefExtensionCToCpp::GetLoaderContext() {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, get_loader_context))
+    return NULL;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  cef_request_context_t* _retval = _struct->get_loader_context(_struct);
+
+  // Return type: refptr_same
+  return CefRequestContextCToCpp::Wrap(_retval);
+}
+
+bool CefExtensionCToCpp::IsLoaded() {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, is_loaded))
+    return false;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  int _retval = _struct->is_loaded(_struct);
+
+  // Return type: bool
+  return _retval ? true : false;
+}
+
+void CefExtensionCToCpp::Unload() {
+  cef_extension_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, unload))
+    return;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  _struct->unload(_struct);
+}
+
+// CONSTRUCTOR - Do not edit by hand.
+
+CefExtensionCToCpp::CefExtensionCToCpp() {}
+
+template <>
+cef_extension_t*
+CefCToCppRefCounted<CefExtensionCToCpp, CefExtension, cef_extension_t>::
+    UnwrapDerived(CefWrapperType type, CefExtension* c) {
+  NOTREACHED() << "Unexpected class type: " << type;
+  return NULL;
+}
+
+#if DCHECK_IS_ON()
+template <>
+base::AtomicRefCount
+    CefCToCppRefCounted<CefExtensionCToCpp, CefExtension, cef_extension_t>::
+        DebugObjCt ATOMIC_DECLARATION;
+#endif
+
+template <>
+CefWrapperType CefCToCppRefCounted<CefExtensionCToCpp,
+                                   CefExtension,
+                                   cef_extension_t>::kWrapperType =
+    WT_EXTENSION;