Add a WebDocument::watchCssSelectors(selectors)

public/web/WebFrameClient.h

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 106 matching lines @@
     // This frame has been detached from the view, but has not been closed yet.
     virtual void frameDetached(WebFrame*) { }
 
     // This frame is about to be closed. This is called after frameDetached,
     // when the document is being unloaded, due to new one committing.
     virtual void willClose(WebFrame*) { }
 
     // This frame's name has changed.
     virtual void didChangeName(WebFrame*, const WebString&) { }
 
+    // Called when a watched CSS selector matches or stops matching.
+    virtual void didMatchCSS(WebFrame*, const WebVector<WebString>& newlyMatchingSelectors, const WebVector<WebString>& stoppedMatchingSelectors) { }

[esprehn, 2013/09/04 06:08:28]

Passing the frame into didMatchCSS is really weird, WebDocument already knows
it's frame, you shouldn't pass one since that just means you can potentially get
the wrong one.

[Jeffrey Yasskin, 2013/09/12 22:09:59]

There's no WebDocument here though, and the WebFrameClient might be a
RenderViewImpl, which is the client for more than one WebFrame.  I need some way
in this callback to figure out which one.

+
     // Load commands -------------------------------------------------------
 
     // The client should handle the navigation externally.
     virtual void loadURLExternally(
         WebFrame*, const WebURLRequest&, WebNavigationPolicy) { }
     virtual void loadURLExternally(
         WebFrame*, const WebURLRequest&, WebNavigationPolicy, const WebString& downloadName) { }
 
 
     // Navigational queries ------------------------------------------------
@@ skipping 224 matching lines @@
     // Extensions3D.h in WebCore/platform/graphics).
     virtual void didLoseWebGLContext(WebFrame*, int) { }
 
 protected:
     ~WebFrameClient() { }
 };
 
 } // namespace WebKit
 
 #endif