Introduce ViewRoot to forward input/view events to native

ui/android/event_handler.cc

+// 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.
+
+#include "ui/android/event_handler.h"
+
+#include "base/android/scoped_java_ref.h"
+#include "jni/EventHandler_jni.h"
+#include "ui/android/view_android.h"
+
+using base::android::JavaParamRef;
+
+namespace ui {
+
+// static
+void SetEventHandler(JNIEnv* env,
+                     const JavaParamRef<jclass>& jcaller,
+                     jlong native_view) {
+  ViewAndroid* view_android = reinterpret_cast<ViewAndroid*>(native_view);
+  view_android->OnSetEventHandler();
+}
+
+// static
+void OnPhysicalBackingSizeChanged(JNIEnv* env,
+                                  const JavaParamRef<jclass>& jcaller,
+                                  jlong native_view,
+                                  int width,
+                                  int height) {
+  ViewAndroid* view_android = reinterpret_cast<ViewAndroid*>(native_view);
+  view_android->OnPhysicalBackingSizeChanged(width, height);
+}
+
+bool RegisterEventHandler(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace content