Introduce ViewRoot to forward 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 1e1b48d96ad7e8f3d11c205758d029ca7617ab9d..ff5a20582c9ff3163ef352d2dc295c98d30df9f5 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
@@ -58,6 +58,7 @@ import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content.browser.SPenSupport;
 import org.chromium.ui.UiUtils;
 import org.chromium.ui.base.DeviceFormFactor;
+import org.chromium.ui.base.ViewRoot;
 import org.chromium.ui.base.WindowAndroid;
 import org.chromium.ui.resources.ResourceManager;
 import org.chromium.ui.resources.dynamics.DynamicResourceLoader;
@@ -123,6 +124,8 @@ 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.
@@ -315,6 +318,8 @@ public class CompositorViewHolder extends CoordinatorLayout
             mCompositorView.getResourceManager().getDynamicResourceLoader().registerResource(
                     R.id.control_container, mControlContainer.getToolbarResourceAdapter());
         }
+
+        mViewRoot = windowAndroid.getViewRoot();
     }
 
     /**
@@ -951,7 +956,8 @@ public class CompositorViewHolder extends CoordinatorLayout
             width = MeasureSpec.getSize(mOverlayContentWidthMeasureSpec);
             height = MeasureSpec.getSize(mOverlayContentHeightMeasureSpec);
         }
-        contentViewCore.onPhysicalBackingSizeChanged(width, height);
+
+        mViewRoot.onPhysicalBackingSizeChanged(width, height);
     }
 
     /**