Introduce ViewRoot forwarding input/view events to native

ui/android/java/src/org/chromium/ui/base/WindowAndroid.java

Index: ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
diff --git a/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java b/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
index ddedf90d80c15890f5b51c7a0a8850c653dfa606..b0f71d403a98b5e484330d07825cba150684c278 100644
--- a/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
+++ b/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
@@ -726,16 +726,6 @@ public class WindowAndroid {
         }
     }
 
-    /**
-     * @return {@link ViewRoot} instance used to forward input/view events down to native.
-     */
-    public ViewRoot getViewRoot() {
-        if (mViewRoot == null) {
-            mViewRoot = nativeGetViewRootForJava(mNativeWindowAndroid);
-        }
-        return mViewRoot;
-    }
-
     private native long nativeInit(int displayId);
     private native void nativeOnVSync(long nativeWindowAndroid,
                                       long vsyncTimeMicros,
@@ -744,5 +734,4 @@ public class WindowAndroid {
     private native void nativeOnActivityStopped(long nativeWindowAndroid);
     private native void nativeOnActivityStarted(long nativeWindowAndroid);
     private native void nativeDestroy(long nativeWindowAndroid);
-    private native ViewRoot nativeGetViewRootForJava(long nativeWindowAndroid);
 }