Introduce ViewRoot forwarding input/view events to native

chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
index ff5a20582c9ff3163ef352d2dc295c98d30df9f5..a6a86080c13965624cc6d34473f9fafe8441d4a3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
@@ -124,13 +124,12 @@ public class CompositorViewHolder extends CoordinatorLayout
     // If we've drawn at least one frame.
     private boolean mHasDrawnOnce;
 
-    private ViewRoot mViewRoot;
-
     /**
      * The information about {@link ContentView} for overlay panel. Used to adjust the backing
      * size of the content accordingly.
      */
     private ContentView mOverlayContentView;
+    private ViewRoot mOverlayViewRoot;
     private int mOverlayContentWidthMeasureSpec = ContentView.DEFAULT_MEASURE_SPEC;
     private int mOverlayContentHeightMeasureSpec = ContentView.DEFAULT_MEASURE_SPEC;
 
@@ -252,12 +251,14 @@ public class CompositorViewHolder extends CoordinatorLayout
 
     /**
      * Set the desired size of the overlay content view.
-     * @param overlayContentView {@link ContentView} used for overlay panel.
+     * @param view {@link ContentView} used for overlay panel.
+     * @param root {@link ViewRoot} used for overlay panel.
      * @param width The width of the content view in {@link MeasureSpec}.
      * @param height The height of the content view in {@link MeasureSpec}.
      */
-    public void setOverlayContentInfo(ContentView overlayContentView, int width, int height) {
-        mOverlayContentView = overlayContentView;
+    public void setOverlayContentInfo(ContentView view, ViewRoot root, int width, int height) {
+        mOverlayContentView = view;
+        mOverlayViewRoot = root;
         mOverlayContentWidthMeasureSpec = width;
         mOverlayContentHeightMeasureSpec = height;
     }
@@ -318,8 +319,6 @@ public class CompositorViewHolder extends CoordinatorLayout
             mCompositorView.getResourceManager().getDynamicResourceLoader().registerResource(
                     R.id.control_container, mControlContainer.getToolbarResourceAdapter());
         }
-
-        mViewRoot = windowAndroid.getViewRoot();
     }
 
     /**
@@ -430,18 +429,26 @@ public class CompositorViewHolder extends CoordinatorLayout
         return mCompositorView;
     }
 
-    private View getActiveView() {
+    private Tab getActiveTab() {
         if (mLayoutManager == null || mTabModelSelector == null) return null;
-        Tab tab = mTabModelSelector.getCurrentTab();
+        return mTabModelSelector.getCurrentTab();
+    }
+
+    private View getActiveView() {
+        Tab tab = getActiveTab();
         return tab != null ? tab.getContentView() : null;
     }
 
     private ContentViewCore getActiveContent() {
-        if (mLayoutManager == null || mTabModelSelector == null) return null;
-        Tab tab = mTabModelSelector.getCurrentTab();
+        Tab tab = getActiveTab();
         return tab != null ? tab.getActiveContentViewCore() : null;
     }
 
+    private ViewRoot getActiveViewRoot() {
+        Tab tab = getActiveTab();
+        return tab != null ? tab.getViewRoot() : null;
+    }
+
     @Override
     protected void onSizeChanged(int w, int h, int oldw, int oldh) {
         super.onSizeChanged(w, h, oldw, oldh);
@@ -952,12 +959,15 @@ public class CompositorViewHolder extends CoordinatorLayout
      */
     private void adjustPhysicalBackingSize(ContentViewCore contentViewCore, int width, int height) {
         ContentView contentView = (ContentView) contentViewCore.getContainerView();
-        if (contentView == mOverlayContentView) {
+        ViewRoot viewRoot;
+        if (contentView != mOverlayContentView) {
+            viewRoot = getActiveViewRoot();
+        } else {
             width = MeasureSpec.getSize(mOverlayContentWidthMeasureSpec);
             height = MeasureSpec.getSize(mOverlayContentHeightMeasureSpec);
+            viewRoot = mOverlayViewRoot;
         }
-
-        mViewRoot.onPhysicalBackingSizeChanged(width, height);
+        if (viewRoot != null) viewRoot.onPhysicalBackingSizeChanged(width, height);
     }
 
     /**