Add layerTreeBuildHelper to control layer tree in ContentViewRenderView

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 0d196af3873c39d03234d7e5511953845727ec82..92eaa7c10cd98dc16ee04b089eb101ed620aa515 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
@@ -43,7 +43,7 @@ public class ContentViewRenderView extends FrameLayout {
     private int mPendingSwapBuffers;
     private boolean mNeedToRender;
 
-    private ContentView mCurrentContentView;
+    protected ContentView mCurrentContentView;
 
     private final Runnable mRenderRunnable = new Runnable() {
         @Override
@@ -60,7 +60,7 @@ public class ContentViewRenderView extends FrameLayout {
     public ContentViewRenderView(Context context, WindowAndroid rootWindow) {
         super(context);
         assert rootWindow != null;
-        mNativeContentViewRenderView = nativeInit(rootWindow.getNativePointer());
+        nativeInit(rootWindow.getNativePointer());
         assert mNativeContentViewRenderView != 0;
 
         mSurfaceView = createSurfaceView(getContext());
@@ -79,14 +79,7 @@ public class ContentViewRenderView extends FrameLayout {
 
             @Override
             public void surfaceCreated(SurfaceHolder holder) {
-                setSurfaceViewBackgroundColor(Color.WHITE);
-
-                assert mNativeContentViewRenderView != 0;
-                nativeSurfaceCreated(mNativeContentViewRenderView);
-
-                mPendingSwapBuffers = 0;
-                mPendingRenders = 0;
-
+                ContentViewRenderView.this.surfaceCreated();
                 onReadyToRender();
             }
 
@@ -105,6 +98,18 @@ public class ContentViewRenderView extends FrameLayout {
                         FrameLayout.LayoutParams.MATCH_PARENT));
     }
 
+    @CalledByNative
+    private void clearNativePtr() {
+        assert mNativeContentViewRenderView != 0;
+        mNativeContentViewRenderView = 0;
+    }
+
+    @CalledByNative
+    private void setNativePtr(long nativePtr) {
+        assert mNativeContentViewRenderView == 0;
+        mNativeContentViewRenderView = nativePtr;
+    }
+
     private class VSyncAdapter implements VSyncManager.Provider, VSyncMonitor.Listener {
         private final VSyncMonitor mVSyncMonitor;
         private boolean mVSyncNotificationEnabled;
@@ -218,7 +223,7 @@ public class ContentViewRenderView extends FrameLayout {
 
         if (contentViewCore != null) {
             contentViewCore.onPhysicalBackingSizeChanged(getWidth(), getHeight());
-            mVSyncAdapter.setVSyncListener(contentViewCore.getVSyncListener(mVSyncAdapter));
+            setVSyncListener(contentViewCore);
         }
     }
 
@@ -230,6 +235,20 @@ public class ContentViewRenderView extends FrameLayout {
     }
 
     /**
+     * Gives inheriting classes a way to carry out tasks on the surfaceCreated() call
+     * for mSurfaceCallback.
+     */
+    protected void surfaceCreated() {
+        setSurfaceViewBackgroundColor(Color.WHITE);
+
+        assert mNativeContentViewRenderView != 0;
+        nativeSurfaceCreated(mNativeContentViewRenderView);
+
+        mPendingSwapBuffers = 0;
+        mPendingRenders = 0;
+    }
+
+    /**
      * This method could be subclassed optionally to provide a custom SurfaceView object to
      * this ContentViewRenderView.
      * @param context The context used to create the SurfaceView object.
@@ -258,6 +277,15 @@ public class ContentViewRenderView extends FrameLayout {
     }
 
     /**
+     * Sets the VSyncListener to mVSync adapter to the provided listener from the
+     * given ContentViewCore.
+     * @param contentViewCore ContentViewCore instance go get the listener from.
+     */
+    protected void setVSyncListener(ContentViewCore contentViewCore) {
+        mVSyncAdapter.setVSyncListener(contentViewCore.getVSyncListener(mVSyncAdapter));
+    }
+
+    /**
      * Enter or leave overlay video mode.
      * @param enabled Whether overlay mode is enabled.
      */
@@ -306,7 +334,10 @@ public class ContentViewRenderView extends FrameLayout {
         if (mPendingSwapBuffers > 0) mPendingSwapBuffers--;
     }
 
-    private void render() {
+    /**
+     * Calls Composite on the native side, finishing the compositing task for current frame.
+     */
+    protected void render() {
         if (mPendingRenders > 0) mPendingRenders--;
 
         // Waiting for the content view contents to be ready avoids compositing
@@ -331,7 +362,7 @@ public class ContentViewRenderView extends FrameLayout {
         }
     }
 
-    private native long nativeInit(long rootWindowNativePointer);
+    private native void nativeInit(long rootWindowNativePointer);
     private native void nativeDestroy(long nativeContentViewRenderView);
     private native void nativeSetCurrentContentView(long nativeContentViewRenderView,
             long nativeContentView);