Keep screen on when there is an active WebRTC session on Android.

content/public/android/java/src/org/chromium/content/browser/ActivityContentVideoViewDelegate.java

 // Copyright (c) 2012 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.
 
 package org.chromium.content.browser;
 
 import android.app.Activity;
 import android.content.Context;
 import android.view.Gravity;
 import android.view.View;
@@ skipping 25 matching lines @@
                         ViewGroup.LayoutParams.MATCH_PARENT,
                         Gravity.CENTER));
     }
 
     @Override
     public void onDestroyContentVideoView() {
         mActivity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
     }
 
     @Override
+    public void keepScreenOn(boolean screenOn) {
+        if (screenOn) {
+            mActivity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+        } else {
+            mActivity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+        }
+    }
+
+    @Override
     public Context getContext() {
         return mActivity;
     }
 
     @Override
     public View getVideoLoadingProgressView() {
         return null;
     }
 }