Introduce ViewRoot to forward input/view events to native

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

Index: ui/android/java/src/org/chromium/ui/base/EventHandler.java
diff --git a/ui/android/java/src/org/chromium/ui/base/EventHandler.java b/ui/android/java/src/org/chromium/ui/base/EventHandler.java
new file mode 100644
index 0000000000000000000000000000000000000000..38a2ba3480dd03af7f8e2e7bc67d47ed565da7aa
--- /dev/null
+++ b/ui/android/java/src/org/chromium/ui/base/EventHandler.java
@@ -0,0 +1,29 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.ui.base;
+
+import org.chromium.base.annotations.JNINamespace;
+
+/**
+ * Class used to forward view, input events down to native.
+ */
+@JNINamespace("ui")
+public class EventHandler {
+    private final long mNativeEventHandler;
+
+    private int mPhysicalBackingWidthPix;
+    private int mPhysicalBackingHeightPix;
+
+    public EventHandler(long nativeEventHandler) {
+        mNativeEventHandler = nativeEventHandler;
+    }
+
+    public void onPhysicalBackingSizeChanged(int width, int height) {
+        nativeOnPhysicalBackingSizeChanged(mNativeEventHandler, width, height);
+    }
+
+    private native void nativeOnPhysicalBackingSizeChanged(long nativeEventHandler,
+            int width, int height);
+}