Use ContentViewCore's container view to keep screen on

ui/android/java/src/org/chromium/ui/ViewAndroid.java

Index: ui/android/java/src/org/chromium/ui/ViewAndroid.java
diff --git a/ui/android/java/src/org/chromium/ui/ViewAndroid.java b/ui/android/java/src/org/chromium/ui/ViewAndroid.java
index 0f0ca116a79c753f2058de2842c15b91ae4ebc2c..97c8e1dcfd3460dbdf857f5148653d079cd0f008 100644
--- a/ui/android/java/src/org/chromium/ui/ViewAndroid.java
+++ b/ui/android/java/src/org/chromium/ui/ViewAndroid.java
@@ -4,6 +4,8 @@
 
 package org.chromium.ui;
 
+import android.view.View;
+
 import org.chromium.base.JNINamespace;
 import org.chromium.ui.ViewAndroidDelegate;
 import org.chromium.ui.WindowAndroid;
@@ -23,6 +25,8 @@ public class ViewAndroid {
     private int mNativeViewAndroid = 0;
     private final ViewAndroidDelegate mViewAndroidDelegate;
     private final WindowAndroid mWindowAndroid;
+    private int mKeepScreenOnCount;
+    private View mKeepScreenOnView;
 
     /**
      * Constructs a View object.
@@ -55,6 +59,29 @@ public class ViewAndroid {
         return mNativeViewAndroid;
     }
 
+    /**
+     * Set KeepScreenOn flag. If the flag already set, increase mKeepScreenOnCount.
+     */
+    public void incrementKeepScreenOnCount() {
+        mKeepScreenOnCount++;
+        if (mKeepScreenOnCount == 1) {
+            mKeepScreenOnView = mViewAndroidDelegate.acquireAnchorView();
+            mKeepScreenOnView.setKeepScreenOn(true);
+        }
+    }
+
+    /**
+     * Decrease mKeepScreenOnCount, if it is decreased to 0, remove the flag.
+     */
+    public void decrementKeepScreenOnCount() {
+        assert mKeepScreenOnCount > 0;
+        mKeepScreenOnCount--;
+        if (mKeepScreenOnCount == 0) {
+            mViewAndroidDelegate.releaseAnchorView(mKeepScreenOnView);
+            mKeepScreenOnView = null;
+        }
+    }
+
     private native int nativeInit(int windowPtr);
     private native void nativeDestroy(int nativeViewAndroid);
 }