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

content/browser/screen_orientation/screen_orientation_provider_android.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_SCREEN_ORIENTATION_SCREEN_ORIENTATION_PROVIDER_ANDROID_H_
 #define CONTENT_BROWSER_SCREEN_ORIENTATION_SCREEN_ORIENTATION_PROVIDER_ANDROID_H_
 
 #include <jni.h>
 
 #include "base/compiler_specific.h"
@@ skipping 15 matching lines @@
 
   // ScreenOrientationProvider
   virtual void LockOrientation(int request_id,
                                blink::WebScreenOrientationLockType) OVERRIDE;
   virtual void UnlockOrientation() OVERRIDE;
   virtual void OnOrientationChange() OVERRIDE;
 
   // WebContentsObserver
   virtual void DidToggleFullscreenModeForTab(bool entered_fullscreen) OVERRIDE;
 
+  // Ask the ScreenOrientationListener (Java) to start accurately listening to
+  // the screen orientation. It keep track of the number of start request if it
+  // is already running an accurate listening.
+  static void StartAccurateListening();
+
+  // Ask the ScreenOrientationListener (Java) to stop accurately listening to
+  // the screen orientation. It will actually stop only if the number of stop
+  // requests matches the number of start requests.
+  static void StopAccurateListening();
+
  private:
   WebContentsImpl* web_contents_impl();
 
   // Whether the passed |lock| matches the current orientation. In other words,
   // whether the orientation will need to change to match the |lock|.
   bool LockMatchesCurrentOrientation(blink::WebScreenOrientationLockType lock);
 
   // Returns the lock type that should be associated with 'natural' lock.
   // Returns WebScreenOrientationLockDefault if the natural lock type can't be
   // found.
@@ skipping 14 matching lines @@
     blink::WebScreenOrientationLockType lock;
   };
   LockInformation* pending_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenOrientationProviderAndroid);
 };
 
 } // namespace content
 
 #endif // CONTENT_BROWSER_SCREEN_ORIENTATION_SCREEN_ORIENTATION_PROVIDER_ANDROID_H_