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

content/public/renderer/render_view_observer.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_RENDERER_RENDER_VIEW_OBSERVER_H_
 #define CONTENT_PUBLIC_RENDERER_RENDER_VIEW_OBSERVER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "content/common/content_export.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
+#include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/WebKit/public/web/WebIconURL.h"
 
 class GURL;
 
 namespace ppapi {
 namespace host {
 class PpapiHost;
 }
 }
 
@@ skipping 37 matching lines @@
   virtual void DidFailProvisionalLoad(WebKit::WebFrame* frame,
                                       const WebKit::WebURLError& error) {}
   virtual void DidCommitProvisionalLoad(WebKit::WebFrame* frame,
                                         bool is_new_navigation) {}
   virtual void DidClearWindowObject(WebKit::WebFrame* frame) {}
   virtual void DidCreateDocumentElement(WebKit::WebFrame* frame) {}
   virtual void FrameCreated(WebKit::WebFrame* parent,
                             WebKit::WebFrame* frame) {}
   virtual void FrameDetached(WebKit::WebFrame* frame) {}
   virtual void FrameWillClose(WebKit::WebFrame* frame) {}
+  virtual void DidMatchCSS(
+      WebKit::WebFrame* frame,
+      const WebKit::WebVector<WebKit::WebString>& newly_matching_selectors,
+      const WebKit::WebVector<WebKit::WebString>& stopped_matching_selectors) {}
   virtual void WillSendSubmitEvent(WebKit::WebFrame* frame,
                                    const WebKit::WebFormElement& form) {}
   virtual void WillSubmitForm(WebKit::WebFrame* frame,
                               const WebKit::WebFormElement& form) {}
   virtual void DidCreateDataSource(WebKit::WebFrame* frame,
                                    WebKit::WebDataSource* ds) {}
   virtual void PrintPage(WebKit::WebFrame* frame, bool user_initiated) {}
   virtual void FocusedNodeChanged(const WebKit::WebNode& node) {}
   virtual void WillCreateMediaPlayer(WebKit::WebFrame* frame,
                                      WebKit::WebMediaPlayerClient* client) {}
@@ skipping 52 matching lines @@
   RenderView* render_view_;
   // The routing ID of the associated RenderView.
   int routing_id_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_RENDER_VIEW_OBSERVER_H_