Poll for Display rotation on Android 4.0 and 4.1 when needed.

content/common/screen_orientation_messages.h

Index: content/common/screen_orientation_messages.h
diff --git a/content/common/screen_orientation_messages.h b/content/common/screen_orientation_messages.h
index c2114d615adebb4c54a7cf0e3197ac5a2806cc3c..2defcc71fa55085d6e4aa9767406ef292d668e25 100644
--- a/content/common/screen_orientation_messages.h
+++ b/content/common/screen_orientation_messages.h
@@ -60,3 +60,17 @@ IPC_MESSAGE_ROUTED2(ScreenOrientationHostMsg_LockRequest,
 // The renderer process requests the browser process to unlock the screen
 // orientation.
 IPC_MESSAGE_ROUTED0(ScreenOrientationHostMsg_Unlock)
+
+// The renderer process is now using the Screen Orientation API and informs the
+// browser process that it should start accurately listening to the screen
+// orientation if it wasn't already.
+// This is only expected to be acted upon when the underlying platform requires
+// heavy work in order to accurately know the screen orientation.
+IPC_MESSAGE_CONTROL0(ScreenOrientationHostMsg_StartListening)
+
+// The renderer process is no longer using the Screen Orientation API and
+// informs the browser process that it can stop accurately listening to the
+// screen orientation if no other process cares about it.
+// This is only expected to be acted upon when the underlying platform requires
+// heavy work in order to accurately know the screen orientation.
+IPC_MESSAGE_CONTROL0(ScreenOrientationHostMsg_StopListening)