Add WasShown/WasHidden to RenderFrameObserver.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index a7a3245b9a8777c4814053beef8bcd636bf0ebf9..996aaad10059a095effd36112bb462646aa2db1d 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -411,6 +411,8 @@ RenderFrameImpl::RenderFrameImpl(RenderViewImpl* render_view, int routing_id)
       g_routing_id_frame_map.Get().insert(std::make_pair(routing_id_, this));
   CHECK(result.second) << "Inserting a duplicate item.";
 
+  render_view_->RegisterRenderFrame(this);
+
 #if defined(OS_ANDROID)
   new JavaBridgeDispatcher(this);
 #endif
@@ -423,6 +425,7 @@ RenderFrameImpl::RenderFrameImpl(RenderViewImpl* render_view, int routing_id)
 RenderFrameImpl::~RenderFrameImpl() {
   FOR_EACH_OBSERVER(RenderFrameObserver, observers_, RenderFrameGone());
   FOR_EACH_OBSERVER(RenderFrameObserver, observers_, OnDestruct());
+  render_view_->UnregisterRenderFrame(this);
   g_routing_id_frame_map.Get().erase(routing_id_);
   RenderThread::Get()->RemoveRoute(routing_id_);
 }
@@ -2882,6 +2885,14 @@ void RenderFrameImpl::OnStop() {
   FOR_EACH_OBSERVER(RenderFrameObserver, observers_, OnStop());
 }
 
+void RenderFrameImpl::WasHidden() {
+  FOR_EACH_OBSERVER(RenderFrameObserver, observers_, WasHidden());
+}
+
+void RenderFrameImpl::WasShown() {
+  FOR_EACH_OBSERVER(RenderFrameObserver, observers_, WasShown());
+}
+
 // Tell the embedding application that the URL of the active page has changed.
 void RenderFrameImpl::UpdateURL(blink::WebFrame* frame) {
   DCHECK(!frame_ || frame_ == frame);