Add EventForwarder for routing touch events

ui/android/event_handler.h

Index: ui/android/event_handler.h
diff --git a/ui/android/event_handler.h b/ui/android/event_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..bd2562685c962732caec37b66bb2f36b8af3fd20
--- /dev/null
+++ b/ui/android/event_handler.h
@@ -0,0 +1,83 @@
+// 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_EVENT_HANDLER_H_
+#define UI_ANDROID_EVENT_HANDLER_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+#include "ui/android/ui_android_export.h"
+
+namespace ui {
+
+class ViewAndroid;
+
+class UI_ANDROID_EXPORT EventHandler {
+ public:
+  EventHandler();
+  base::android::ScopedJavaLocalRef<jobject> CreateJavaObject();
+
+  static EventHandler* Create(ViewAndroid* view);
+
+  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);
+
+  jboolean OnMouseEvent(JNIEnv* env,
+                        const base::android::JavaParamRef<jobject>& obj,
+                        jlong time_ms,
+                        jint android_action,
+                        jfloat x,
+                        jfloat y,
+                        jint pointer_id,
+                        jfloat pressure,
+                        jfloat orientation,
+                        jfloat tilt,
+                        jint android_changed_button,
+                        jint android_button_state,
+                        jint android_meta_state,
+                        jint tool_type);
+
+ private:
+  explicit EventHandler(ViewAndroid* view);
+
+  ViewAndroid* const view_;
+  float dip_scale_;
+
+  DISALLOW_COPY_AND_ASSIGN(EventHandler);
+};
+
+bool RegisterEventHandler(JNIEnv* env);
+
+}  // namespace ui
+
+#endif  // UI_ANDROID_EVENT_HANDLER_H_