Reimplement web content accessibility by caching in browser process

chrome/browser/renderer_host/render_view_host.h

Index: chrome/browser/renderer_host/render_view_host.h
===================================================================
--- chrome/browser/renderer_host/render_view_host.h	(revision 46908)
+++ chrome/browser/renderer_host/render_view_host.h	(working copy)
@@ -22,6 +22,7 @@
 #include "third_party/WebKit/WebKit/chromium/public/WebPopupType.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebTextDirection.h"
 #include "webkit/glue/password_form_dom_manager.h"
+#include "webkit/glue/webaccessibility.h"
 #include "webkit/glue/window_open_disposition.h"
 
 class FilePath;
@@ -464,6 +465,9 @@
   // changed.
   void EnablePreferredSizeChangedMode();
 
+  // Requests a snapshot of an accessible DOM tree from the renderer.
+  void RequestAccessibilityTree();
+
  protected:
   // RenderWidgetHost protected overrides.
   virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
@@ -625,6 +629,7 @@
   void OnExtensionPostMessage(int port_id, const std::string& message);
   void OnAccessibilityFocusChange(int acc_obj_id);
   void OnAccessibilityObjectStateChange(int acc_obj_id);
+  void OnAccessibilityTree(const webkit_glue::WebAccessibility& tree);
   void OnCSSInserted();
   void OnPageContents(const GURL& url,
                       int32 page_id,