Introduce ViewRoot forwarding input/view events to native

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

Index: ui/android/java/src/org/chromium/ui/base/ViewRoot.java
diff --git a/ui/android/java/src/org/chromium/ui/base/ViewRoot.java b/ui/android/java/src/org/chromium/ui/base/ViewRoot.java
index c224e8e3ed8c9cdfd31b3ed2e783e090ea42a4e7..e4ac856a6b74c0cc035ac6969311710fc4a84148 100644
--- a/ui/android/java/src/org/chromium/ui/base/ViewRoot.java
+++ b/ui/android/java/src/org/chromium/ui/base/ViewRoot.java
@@ -20,13 +20,12 @@ public class ViewRoot {
     // the native instance is alive.
     private long mNativeView;
 
-    @CalledByNative
-    private static ViewRoot create(long nativeView) {
-        return new ViewRoot(nativeView);
+    public static ViewRoot create(WindowAndroid window) {
+        return new ViewRoot(window);
     }
 
-    private ViewRoot(long nativeView) {
-        mNativeView = nativeView;
+    private ViewRoot(WindowAndroid window) {
+        mNativeView = nativeInit(window.getNativePointer());
     }
 
     /**
@@ -41,10 +40,16 @@ public class ViewRoot {
     }
 
     @CalledByNative
+    private long getNativePtr() {
+        return mNativeView;
+    }
+
+    @CalledByNative
     private void onDestroyNativeView() {
         mNativeView = 0;
     }
 
-    private static native void nativeOnPhysicalBackingSizeChanged(long viewAndroid,
+    private native long nativeInit(long windowNativePointer);
+    private native void nativeOnPhysicalBackingSizeChanged(long nativeViewRoot,
             int width, int height);
 }