Use ContainerView for PowerSaveBlocker to keep screen on

device/power_save_blocker/android/java/src/org/chromium/device/power_save_blocker/PowerSaveBlocker.java

Index: device/power_save_blocker/android/java/src/org/chromium/device/power_save_blocker/PowerSaveBlocker.java
diff --git a/device/power_save_blocker/android/java/src/org/chromium/device/power_save_blocker/PowerSaveBlocker.java b/device/power_save_blocker/android/java/src/org/chromium/device/power_save_blocker/PowerSaveBlocker.java
index c29dfe32eb80650bf604b936c3918272af42eb35..43dead5d00f7ed98d23fd28f2207052df895c0e2 100644
--- a/device/power_save_blocker/android/java/src/org/chromium/device/power_save_blocker/PowerSaveBlocker.java
+++ b/device/power_save_blocker/android/java/src/org/chromium/device/power_save_blocker/PowerSaveBlocker.java
@@ -9,12 +9,9 @@ import android.view.View;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 
-import java.lang.ref.WeakReference;
-
 @JNINamespace("device")
 class PowerSaveBlocker {
-    // WeakReference to prevent leaks in Android WebView.
-    private WeakReference<View> mKeepScreenOnView;
+    private View mKeepScreenOnView;

[boliu, 2017/01/18 18:21:16]

the weakreference here is not because native side holds onto view, but because
native side holds onto PowerSaveBlocker

ie the weakreference here is still required

[Jinsuk Kim, 2017/01/19 23:48:08]

Done.

 
     @CalledByNative
     private static PowerSaveBlocker create() {
@@ -24,21 +21,16 @@ class PowerSaveBlocker {
     private PowerSaveBlocker() {}
 
     @CalledByNative
-    private void applyBlock(View anchorView) {
+    private void applyBlock(View view) {
         assert mKeepScreenOnView == null;
-        mKeepScreenOnView = new WeakReference<>(anchorView);
-        anchorView.setKeepScreenOn(true);
+        mKeepScreenOnView = view;
+        view.setKeepScreenOn(true);
     }
 
     @CalledByNative
     private void removeBlock() {
-        // mKeepScreenOnView may be null since it's possible that |applyBlock()|
-        // was not invoked due to having failed to acquire an anchor view.
-        if (mKeepScreenOnView == null) return;
-        View anchorView = mKeepScreenOnView.get();
-        mKeepScreenOnView = null;
-        if (anchorView == null) return;
-
-        anchorView.setKeepScreenOn(false);
+        // mKeepScreenOnView may be null since it's possible that |applyBlock()| was
+        // not invoked due to having failed to get a view to call |setKeepScrenOn| on.
+        if (mKeepScreenOnView != null) mKeepScreenOnView.setKeepScreenOn(false);
     }
 }