Add WasShown/WasHidden to RenderFrameObserver.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 835f6e70841288bd6687f9aad5693a266f498d2e..1bde1e8efce5960f6e60929836bb0a0d23ca4eb6 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -13,6 +13,8 @@
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
+#include "content/browser/renderer_host/render_widget_host_impl.h"

[jam, 2014/05/28 17:55:37]

nit: personally i wouldn't include such big headers in another header if i can
avoid it, and instead i would move the implementation of the method to the cc
file (and rename it to GetRenderWidgetHostImpl accordingly)

[nasko, 2014/05/28 18:26:11]

Done.

 #include "content/common/content_export.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/common/javascript_message_type.h"
@@ -39,6 +41,7 @@ class RenderFrameHostDelegate;
 class RenderFrameProxyHost;
 class RenderProcessHost;
 class RenderViewHostImpl;
+class RenderWidgetHostImpl;
 struct ContextMenuParams;
 struct GlobalRequestID;
 struct Referrer;
@@ -80,6 +83,11 @@ class CONTENT_EXPORT RenderFrameHostImpl : public RenderFrameHost {
   RenderViewHostImpl* render_view_host() { return render_view_host_; }
   RenderFrameHostDelegate* delegate() { return delegate_; }
   FrameTreeNode* frame_tree_node() { return frame_tree_node_; }
+  // TODO(nasko): The RenderWidgetHost will be owned by RenderFrameHost in
+  // the future, so update this accessor to return the right pointer.
+  RenderWidgetHostImpl* render_widget_host() {
+    return static_cast<RenderWidgetHostImpl*>(render_view_host_);
+  }
 
   // This function is called when this is a swapped out RenderFrameHost that
   // lives in the same process as the parent frame. The