Implement vsync notification on Android

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

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewRenderView.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewRenderView.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewRenderView.java
index c3f6c26e144aca71bab32dc5a43425d30e78bd0a..6c5971b1b88e5ae0d449ec679369218d76a6a7a7 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewRenderView.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewRenderView.java
@@ -25,17 +25,10 @@ public class ContentViewRenderView extends FrameLayout {
     private int mNativeContentViewRenderView = 0;
 
     private SurfaceView mSurfaceView;
+    private VSyncAdapter mVSyncAdapter;
 
     private ContentView mCurrentContentView;
 
-    private final VSyncMonitor mVSyncMonitor;
-
-    // The VSyncMonitor gives the timebase for the actual vsync, but we don't want render until
-    // we have had a chance for input events to propagate to the compositor thread. This takes
-    // 3 ms typically, so we adjust the vsync timestamps forward by a bit to give input events a
-    // chance to arrive.
-    private static final long INPUT_EVENT_LAG_FROM_VSYNC_MICROSECONDS = 3200;
-
     /**
      * Constructs a new ContentViewRenderView that should be can to a view hierarchy.
      * Native code should add/remove the layers to be rendered through the ContentViewLayerRenderer.
@@ -70,24 +63,55 @@ public class ContentViewRenderView extends FrameLayout {
             }
         });
 
-        mVSyncMonitor = new VSyncMonitor(getContext(), new VSyncMonitor.Listener() {
-            @Override
-            public void onVSync(VSyncMonitor monitor, long vsyncTimeMicros) {
-                if (mCurrentContentView == null) return;
+        mVSyncAdapter = new VSyncAdapter(getContext());
+        addView(mSurfaceView,
+                new FrameLayout.LayoutParams(
+                        FrameLayout.LayoutParams.MATCH_PARENT,
+                        FrameLayout.LayoutParams.MATCH_PARENT));
+    }
+
+    private static class VSyncAdapter implements VSyncManager.Provider, VSyncMonitor.Listener {
+        private final VSyncMonitor mVSyncMonitor;
+        private boolean mVSyncNotificationEnabled;
+        private VSyncManager.Listener mVSyncListener;
+
+        // The VSyncMonitor gives the timebase for the actual vsync, but we don't want render until
+        // we have had a chance for input events to propagate to the compositor thread. This takes
+        // 3 ms typically, so we adjust the vsync timestamps forward by a bit to give input events a
+        // chance to arrive.
+        private static final long INPUT_EVENT_LAG_FROM_VSYNC_MICROSECONDS = 3200;
+
+        VSyncAdapter(Context context) {
+            mVSyncMonitor = new VSyncMonitor(context, this);
+        }
+
+        @Override
+        public void onVSync(VSyncMonitor monitor, long vsyncTimeMicros) {
+            if (mVSyncListener == null) return;
+            if (mVSyncNotificationEnabled) {
+                mVSyncListener.onVSync(vsyncTimeMicros);
+                mVSyncMonitor.requestUpdate();
+            } else {
                 // Compensate for input event lag. Input events are delivered immediately on
                 // pre-JB releases, so this adjustment is only done for later versions.
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                     vsyncTimeMicros += INPUT_EVENT_LAG_FROM_VSYNC_MICROSECONDS;
                 }
-                mCurrentContentView.getContentViewCore().updateVSync(vsyncTimeMicros,
+                mVSyncListener.updateVSync(vsyncTimeMicros,
                         mVSyncMonitor.getVSyncPeriodInMicroseconds());
             }
-        });
-
-        addView(mSurfaceView,
-                new FrameLayout.LayoutParams(
-                        FrameLayout.LayoutParams.MATCH_PARENT,
-                        FrameLayout.LayoutParams.MATCH_PARENT));
+        }
+
+        @Override
+        public void setVSyncNotificationEnabled(VSyncManager.Listener listener, boolean enabled) {
+            if (enabled && !mVSyncNotificationEnabled) mVSyncMonitor.requestUpdate();
+            mVSyncNotificationEnabled = enabled;
+        }
+
+        void setVSyncListener(VSyncManager.Listener listener) {
+            mVSyncListener = listener;
+            if (mVSyncListener != null) mVSyncMonitor.requestUpdate();
+        }
     }
 
     /**
@@ -102,13 +126,13 @@ public class ContentViewRenderView extends FrameLayout {
      * Makes the passed ContentView the one displayed by this ContentViewRenderView.
      */
     public void setCurrentContentView(ContentView contentView) {
+        ContentViewCore contentViewCore = contentView.getContentViewCore();
         nativeSetCurrentContentView(mNativeContentViewRenderView,
-                contentView.getContentViewCore().getNativeContentViewCore());
+                contentViewCore.getNativeContentViewCore());
 
         mCurrentContentView = contentView;
-        mCurrentContentView.getContentViewCore().onPhysicalBackingSizeChanged(
-                getWidth(), getHeight());
-        mVSyncMonitor.requestUpdate();
+        contentViewCore.onPhysicalBackingSizeChanged(getWidth(), getHeight());
+        mVSyncAdapter.setVSyncListener(contentViewCore.getVSyncListener(mVSyncAdapter));
     }
 
     /**