Implements frame sniffer to watch iframe loading state.

content/renderer/render_view.cc

Index: content/renderer/render_view.cc
diff --git a/content/renderer/render_view.cc b/content/renderer/render_view.cc
index a6e16c8f23dad020b855f0c38d7bf0a4b96bf615..d8eba11f328c317c2cbc986f75f5c66f81de755f 100644
--- a/content/renderer/render_view.cc
+++ b/content/renderer/render_view.cc
@@ -44,6 +44,7 @@
 #include "content/renderer/content_renderer_client.h"
 #include "content/renderer/devtools_agent.h"
 #include "content/renderer/device_orientation_dispatcher.h"
+#include "content/renderer/frame_sniffer.h"
 #include "content/renderer/mhtml_generator.h"
 #include "content/renderer/external_popup_menu.h"
 #include "content/renderer/geolocation_dispatcher.h"
@@ -713,6 +714,7 @@ bool RenderView::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ViewMsg_SetHistoryLengthAndPrune,
                         OnSetHistoryLengthAndPrune)
     IPC_MESSAGE_HANDLER(ViewMsg_EnableViewSourceMode, OnEnableViewSourceMode)
+    IPC_MESSAGE_HANDLER(ViewMsg_StartFrameSniffer, OnStartFrameSniffer)
 
     // Have the super handle all other messages.
     IPC_MESSAGE_UNHANDLED(handled = RenderWidget::OnMessageReceived(message))
@@ -4592,3 +4594,7 @@ void RenderView::OnEnableViewSourceMode() {
     return;
   main_frame->enableViewSourceMode(true);
 }
+
+void RenderView::OnStartFrameSniffer(const string16& frame_name) {
+  new FrameSniffer(this, frame_name);
+}