content: convert accessibility notifications to observer usage

content/browser/renderer_host/render_view_host_impl.h

Index: content/browser/renderer_host/render_view_host_impl.h
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index 7d57852228eed7aa35d9390d22bdea8f6a2efc11..b3fa7c46e63bf4fb517dc6bba9422476a2b64241 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -422,6 +422,12 @@ class CONTENT_EXPORT RenderViewHostImpl
     return accessibility_tree_;
   }
 
+  // Set accessibility callbacks (only for testing).

[jam, 2013/02/14 00:39:01]

nit: (only for testing). is redundant given the method names

also can you move these to line 417? usually the convention is to put simple
getters after method declarations

[Paweł Hajdan Jr., 2013/02/14 09:28:11]

Done.

+  void SetAccessibilityLayoutCompleteCallbackForTesting(
+      const base::Closure& callback);
+  void SetAccessibilityLoadCompleteCallbackForTesting(
+      const base::Closure& callback);
+
   bool is_waiting_for_unload_ack_for_testing() {
     return is_waiting_for_unload_ack_;
   }
@@ -652,6 +658,10 @@ class CONTENT_EXPORT RenderViewHostImpl
   // callbacks.
   std::map<int, JavascriptResultCallback> javascript_callbacks_;
 
+  // Accessibility callbacks.
+  base::Closure accessibility_layout_callback_;
+  base::Closure accessibility_load_callback_;
+
   // True if the render view can be shut down suddenly.
   bool sudden_termination_allowed_;