ViewRoot class for event forwarding on Android

ui/android/view_root.h

+// Copyright 2017 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.
+
+#ifndef UI_ANDROID_VIEW_ROOT_H_
+#define UI_ANDROID_VIEW_ROOT_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+#include "ui/android/ui_android_export.h"
+#include "ui/android/view_android.h"
+
+namespace ui {
+
+// ViewRoot is the root of a ViewAndroid tree.
+// TODO(jinsukkim): Hook this up to UI event forwarding flow and
+//     substitute WindowAndroid. See https://crbug.com/671401
+class UI_ANDROID_EXPORT ViewRoot : public ViewAndroid {
+ public:
+  explicit ViewRoot(jlong window_android_ptr);
+
+  void Destroy(JNIEnv* env,
+               const base::android::JavaParamRef<jobject>& obj);
+
+  // ViewAndroid overrides.
+  WindowAndroid* GetWindowAndroid() const override;
+  ViewAndroid* GetViewRoot() override;
+
+  // Move the give child ViewAndroid to the front of the list
+  // so that it can be the first responder of events.
+  void MoveToFront(ViewAndroid* child);
+
+  jboolean OnTouchEvent(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jobject>& motion_event,
+      jlong time_ms,
+      jint android_action,
+      jint pointer_count,
+      jint history_size,
+      jint action_index,
+      jfloat pos_x_0,
+      jfloat pos_y_0,
+      jfloat pos_x_1,
+      jfloat pos_y_1,
+      jint pointer_id_0,
+      jint pointer_id_1,
+      jfloat touch_major_0,
+      jfloat touch_major_1,
+      jfloat touch_minor_0,
+      jfloat touch_minor_1,
+      jfloat orientation_0,
+      jfloat orientation_1,
+      jfloat tilt_0,
+      jfloat tilt_1,
+      jfloat raw_pos_x,
+      jfloat raw_pos_y,
+      jint android_tool_type_0,
+      jint android_tool_type_1,
+      jint android_button_state,
+      jint android_meta_state,
+      jboolean is_touch_handle_event);
+
+ private:
+  WindowAndroid* window_;
+
+  DISALLOW_COPY_AND_ASSIGN(ViewRoot);
+};
+
+bool RegisterViewRoot(JNIEnv* env);
+
+}  // namespace ui
+
+#endif  // UI_ANDROID_VIEW_ROOT_H_