Chromium plumbing for Screen Orientation API orientationchange events.

content/browser/renderer_host/render_process_host_impl.h

Index: content/browser/renderer_host/render_process_host_impl.h
diff --git a/content/browser/renderer_host/render_process_host_impl.h b/content/browser/renderer_host/render_process_host_impl.h
index 2fea65613408453a2a9add5309e06e6d5529879e..d2fbe9a5599def233956b3e7a109e8ed8db016d1 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -46,6 +46,7 @@ class RenderWidgetHelper;
 class RenderWidgetHost;
 class RenderWidgetHostImpl;
 class RenderWidgetHostViewFrameSubscriber;
+class ScreenOrientationDispatcherHost;
 class StoragePartition;
 class StoragePartitionImpl;
 
@@ -169,6 +170,9 @@ class CONTENT_EXPORT RenderProcessHostImpl
   void WebRtcLogMessage(const std::string& message);
 #endif
 
+  scoped_refptr<ScreenOrientationDispatcherHost>
+      screen_orientation_dispatcher_host() const;

[ostap, 2014/02/20 20:51:12]

Don't really understand how this should work.
RenderPorcessHostImpl will keep pointer at the instance of
ScreenOrientationDispatcherHost instance and also add it to filter list. At the
same time returned scoped_refptr might deallocate this instance outside of
RenderPorcessHostImpl . Isn't it a problem here?
Actually, where screen_orientation_dispatcher_host() will be used? Is it
necessary?

[mlamouri (slow - plz ping), 2014/02/20 21:07:05]

It would be used in order to send a message to the renderer process. 
See https://codereview.chromium.org/172473004/

+
   // Register/unregister the host identified by the host id in the global host
   // list.
   static void RegisterHost(int host_id, RenderProcessHost* host);
@@ -408,6 +412,9 @@ class CONTENT_EXPORT RenderProcessHostImpl
   // Lives on the browser's ChildThread.
   base::WeakPtrFactory<RenderProcessHostImpl> weak_factory_;
 
+  // Message filter and dispatcher for screen orientation.
+  ScreenOrientationDispatcherHost* screen_orientation_dispatcher_host_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderProcessHostImpl);
 };