Use Blink support to watch CSS selectors directly instead of using a MutationObserver.

chrome/renderer/extensions/dispatcher.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/extensions/dispatcher.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/json/json_reader.h"
@@ skipping 378 matching lines @@
     arguments.push_back(converter->ToV8Value(*it, context->v8_context()));
   }
 
   context->module_system()->CallModuleMethod(
       module_name, method_name, &arguments);
 }
 
 }  // namespace
 
 Dispatcher::Dispatcher()
-    : content_watcher_(new ContentWatcher(this)),
+    : content_watcher_(new ContentWatcher()),
       is_webkit_initialized_(false),
       webrequest_adblock_(false),
       webrequest_adblock_plus_(false),
       webrequest_other_(false),
       source_map_(&ResourceBundle::GetSharedInstance()),
       v8_schema_registry_(new V8SchemaRegistry) {
   const CommandLine& command_line = *(CommandLine::ForCurrentProcess());
   is_extension_process_ =
       command_line.HasSwitch(switches::kExtensionProcess) ||
       command_line.HasSwitch(switches::kSingleProcess);
@@ skipping 412 matching lines @@
   module_system->RegisterNativeHandler("messaging_natives",
       scoped_ptr<NativeHandler>(MessagingBindings::Get(this, context)));
   module_system->RegisterNativeHandler("apiDefinitions",
       scoped_ptr<NativeHandler>(new ApiDefinitionsNatives(this, context)));
   module_system->RegisterNativeHandler("sendRequest",
       scoped_ptr<NativeHandler>(
           new SendRequestNatives(this, request_sender_.get(), context)));
   module_system->RegisterNativeHandler("setIcon",
       scoped_ptr<NativeHandler>(
           new SetIconNatives(this, request_sender_.get(), context)));
-  module_system->RegisterNativeHandler(
-      "contentWatcherNative",
-      content_watcher_->MakeNatives(context));
   module_system->RegisterNativeHandler("activityLogger",
       scoped_ptr<NativeHandler>(new APIActivityLogger(this, context)));
   module_system->RegisterNativeHandler("renderViewObserverNatives",
       scoped_ptr<NativeHandler>(new RenderViewObserverNatives(this, context)));
 
   // Natives used by multiple APIs.
   module_system->RegisterNativeHandler("file_system_natives",
       scoped_ptr<NativeHandler>(new FileSystemNatives(context)));
 
   // Custom bindings.
@@ skipping 46 matching lines @@
   module_system->RegisterNativeHandler("runtime",
       scoped_ptr<NativeHandler>(new RuntimeCustomBindings(this, context)));
   module_system->RegisterNativeHandler("tabs",
       scoped_ptr<NativeHandler>(new TabsCustomBindings(this, context)));
   module_system->RegisterNativeHandler("webstore",
       scoped_ptr<NativeHandler>(new WebstoreBindings(this, context)));
 }
 
 void Dispatcher::PopulateSourceMap() {
   // Libraries.
-  source_map_.RegisterSource("contentWatcher", IDR_CONTENT_WATCHER_JS);
   source_map_.RegisterSource("entryIdManager", IDR_ENTRY_ID_MANAGER);
   source_map_.RegisterSource(kEventBindings, IDR_EVENT_BINDINGS_JS);
   source_map_.RegisterSource("imageUtil", IDR_IMAGE_UTIL_JS);
   source_map_.RegisterSource("json_schema", IDR_JSON_SCHEMA_JS);
   source_map_.RegisterSource("lastError", IDR_LAST_ERROR_JS);
   source_map_.RegisterSource("messaging", IDR_MESSAGING_JS);
   source_map_.RegisterSource("messaging_utils", IDR_MESSAGING_UTILS_JS);
   source_map_.RegisterSource(kSchemaUtils, IDR_SCHEMA_UTILS_JS);
   source_map_.RegisterSource("sendRequest", IDR_SEND_REQUEST_JS);
   source_map_.RegisterSource("setIcon", IDR_SET_ICON_JS);
@@ skipping 299 matching lines @@
                                      "$FONTFAMILY", system_font_family_);
     ReplaceFirstSubstringAfterOffset(&stylesheet, 0,
                                      "$FONTSIZE", system_font_size_);
     frame->document().insertUserStyleSheet(
         WebString::fromUTF8(stylesheet), WebDocument::UserStyleUserLevel);
   }
 
   content_watcher_->DidCreateDocumentElement(frame);
 }
 
+void Dispatcher::DidMatchCSS(
+    WebKit::WebFrame* frame,
+    const WebKit::WebVector<WebKit::WebString>& newly_matching_selectors,
+    const WebKit::WebVector<WebKit::WebString>& stopped_matching_selectors) {
+  content_watcher_->DidMatchCSS(
+      frame, newly_matching_selectors, stopped_matching_selectors);
+}
+
+
 void Dispatcher::OnActivateExtension(const std::string& extension_id) {
   const Extension* extension = extensions_.GetByID(extension_id);
   if (!extension) {
     // Extension was activated but was never loaded. This probably means that
     // the renderer failed to load it (or the browser failed to tell us when it
     // did). Failures shouldn't happen, but instead of crashing there (which
     // executes on all renderers) be conservative and only crash in the renderer
     // of the extension which failed to load; this one.
     std::string& error = extension_load_errors_[extension_id];
     char minidump[256];
@@ skipping 330 matching lines @@
     RenderView* background_view =
         ExtensionHelper::GetBackgroundPage(extension_id);
     if (background_view) {
       background_view->Send(new ExtensionHostMsg_EventAck(
           background_view->GetRoutingID()));
     }
   }
 }
 
 }  // namespace extensions