chrome: Add CEF-specific WebUI handling (see issue #2969)

To avoid conflicting IDs between Alloy (which uses cef.pak) and Chrome
(which uses chrome_100_percent.pak) the cef/LICENSE.txt file is now included
in both cef/libcef/resources/cef_resources.grd and
chrome/app/theme/chrome_unscaled_resources.grd with different ID values.

The cef.pak file currently contains both CEF-specific resources and Chrome
resources that are already included in the default *.pak files distributed
with Chrome. In the future we should remove this duplication and just
distribute the same *.pak files as Chrome for the majority of resources.

libcef/browser/chrome/chrome_browser_main_extra_parts_cef.cc

@@ -5,6 +5,7 @@
 #include "libcef/browser/chrome/chrome_browser_main_extra_parts_cef.h"
 
 #include "libcef/browser/context.h"
+#include "libcef/browser/net/chrome_scheme_handler.h"
 
 #include "base/task/post_task.h"
 
@@ -31,4 +32,6 @@ void ChromeBrowserMainExtraPartsCef::PreMainMessageLoopRun() {
   user_blocking_task_runner_ = base::CreateSingleThreadTaskRunner(
       {base::ThreadPool(), base::TaskPriority::USER_BLOCKING,
        base::TaskShutdownBehavior::BLOCK_SHUTDOWN, base::MayBlock()});
+
+  scheme::RegisterWebUIControllerFactory();
 }

libcef/browser/chrome/chrome_content_browser_client_cef.cc

@@ -8,6 +8,7 @@
 #include "libcef/browser/browser_info_manager.h"
 #include "libcef/browser/browser_message_filter.h"
 #include "libcef/browser/chrome/chrome_browser_main_extra_parts_cef.h"
+#include "libcef/browser/net/chrome_scheme_handler.h"
 #include "libcef/browser/net/throttle_handler.h"
 #include "libcef/browser/net_service/cookie_manager_impl.h"
 #include "libcef/browser/net_service/login_delegate.h"
@@ -283,6 +284,17 @@ ChromeContentBrowserClientCef::CreateLoginDelegate(
       response_headers, first_auth_attempt, std::move(auth_required_callback));
 }
 
+void ChromeContentBrowserClientCef::BrowserURLHandlerCreated(
+    content::BrowserURLHandler* handler) {
+  scheme::BrowserURLHandlerCreated(handler);
+  ChromeContentBrowserClient::BrowserURLHandlerCreated(handler);
+}
+
+bool ChromeContentBrowserClientCef::IsWebUIAllowedToMakeNetworkRequests(
+    const url::Origin& origin) {
+  return scheme::IsWebUIAllowedToMakeNetworkRequests(origin);
+}
+
 CefRefPtr<CefRequestContextImpl>
 ChromeContentBrowserClientCef::request_context() const {
   return browser_main_parts_->request_context();

libcef/browser/chrome/chrome_content_browser_client_cef.h

@@ -91,6 +91,8 @@ class ChromeContentBrowserClientCef : public ChromeContentBrowserClient {
       scoped_refptr<net::HttpResponseHeaders> response_headers,
       bool first_auth_attempt,
       LoginAuthRequiredCallback auth_required_callback) override;
+  void BrowserURLHandlerCreated(content::BrowserURLHandler* handler) override;
+  bool IsWebUIAllowedToMakeNetworkRequests(const url::Origin& origin) override;
 
   CefRefPtr<CefRequestContextImpl> request_context() const;
 

libcef/browser/net/chrome_scheme_handler.cc

@@ -17,6 +17,7 @@
 #include "libcef/browser/net/internal_scheme_handler.h"
 #include "libcef/browser/thread_util.h"
 #include "libcef/common/app_manager.h"
+#include "libcef/features/runtime.h"
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
@@ -34,6 +35,7 @@
 #include "chrome/browser/ui/webui/chrome_web_ui_controller_factory.h"
 #include "chrome/browser/ui/webui/theme_source.h"
 #include "chrome/common/url_constants.h"
+#include "chrome/grit/chrome_unscaled_resources.h"
 #include "content/browser/renderer_host/debug_urls.h"
 #include "content/browser/webui/content_web_ui_controller_factory.h"
 #include "content/public/browser/browser_url_handler.h"
@@ -164,6 +166,10 @@ bool IsUnlistedHost(const std::string& host) {
 
 // Returns true if a host is WebUI and should be allowed to load.
 bool IsAllowedWebUIHost(const std::string& host) {
+  // Chrome runtime allows all WebUI hosts.
+  if (cef::IsChromeRuntimeEnabled())
+    return true;
+
   // Explicitly whitelisted WebUI hosts.
   for (size_t i = 0;
        i < sizeof(kAllowedWebUIHosts) / sizeof(kAllowedWebUIHosts[0]); ++i) {
@@ -285,6 +291,18 @@ class TemplateParser {
 };
 
 bool OnExtensionsSupportUI(std::string* mime_type, std::string* output) {
+  *mime_type = "text/html";
+
+  if (cef::IsChromeRuntimeEnabled()) {
+    // Redirect to the Chrome documentation.
+    *output =
+        "<html><head>\n"
+        "<meta http-equiv=\"refresh\" "
+        "content=\"0;URL='https://developer.chrome.com/docs/extensions/'\"/>\n"
+        "</head></html>\n";
+    return true;
+  }
+
   static const char kDevURL[] = "https://developer.chrome.com/extensions/";
 
   std::string html =
@@ -331,16 +349,22 @@ bool OnExtensionsSupportUI(std::string* mime_type, std::string* output) {
 
   html += "</ul>\n</body>\n</html>";
 
-  *mime_type = "text/html";
   *output = html;
-
   return true;
 }
 
 bool OnLicenseUI(std::string* mime_type, std::string* output) {
+  // TODO(chrome): Currently, CEF-specific resources for the Alloy runtime come
+  // from cef/libcef/resources/cef_resources.grd via cef.pak and CEF-specific
+  // resources for the Chrome runtime come from
+  // chrome/app/theme/chrome_unscaled_resources.grd via chrome_100_percent.pak.
+  // It would be better to have a single pak file (and single ID value) for
+  // CEF-specific resources and share the same *.pak files as Chrome for the
+  // other resources.
   std::string piece =
       ui::ResourceBundle::GetSharedInstance().LoadDataResourceString(
-          IDR_CEF_LICENSE_TXT);
+          cef::IsChromeRuntimeEnabled() ? IDR_CHROME_CEF_LICENSE_TXT
+                                        : IDR_CEF_LICENSE_TXT);
   if (piece.empty()) {
     NOTREACHED() << "Failed to load license txt resource.";
     return false;

patch/patches/chrome_runtime.patch

@@ -77,6 +77,18 @@ index db85b6b2fcf5..bcf6867e8f4e 100644
  }
  
  #endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
+diff --git chrome/app/theme/chrome_unscaled_resources.grd chrome/app/theme/chrome_unscaled_resources.grd
+index b4e4545e3520..29335f1614e2 100644
+--- chrome/app/theme/chrome_unscaled_resources.grd
++++ chrome/app/theme/chrome_unscaled_resources.grd
+@@ -62,6 +62,7 @@
+         </if>
+       </if>
+       <if expr="not _google_chrome">
++        <include name="IDR_CHROME_CEF_LICENSE_TXT" file="../../../cef/LICENSE.txt" type="BINDATA" />
+         <include name="IDR_PRODUCT_LOGO_64" file="chromium/product_logo_64.png" type="BINDATA" />
+         <include name="IDR_PRODUCT_LOGO_128" file="chromium/product_logo_128.png" type="BINDATA" />
+         <include name="IDR_PRODUCT_LOGO_256" file="chromium/product_logo_256.png" type="BINDATA" />
 diff --git chrome/browser/chrome_browser_main.cc chrome/browser/chrome_browser_main.cc
 index fee4d5f1a8ca..2e4fb506d851 100644
 --- chrome/browser/chrome_browser_main.cc