blimp: Add support for input handling

blimp/client/input/blimp_input_handler_wrapper.h

Index: blimp/client/input/blimp_input_handler_wrapper.h
diff --git a/blimp/client/input/blimp_input_handler_wrapper.h b/blimp/client/input/blimp_input_handler_wrapper.h
new file mode 100644
index 0000000000000000000000000000000000000000..e7b5e5a7173ea746d583c84387e85f3c7d30e60f
--- /dev/null
+++ b/blimp/client/input/blimp_input_handler_wrapper.h
@@ -0,0 +1,59 @@
+// Copyright 2011 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 BLIMP_CLIENT_INPUT_BLIMP_INPUT_HANDLER_WRAPPER_H_
+#define BLIMP_CLIENT_INPUT_BLIMP_INPUT_HANDLER_WRAPPER_H_
+
+#include "base/macros.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_checker.h"
+#include "ui/events/blink/input_handler_proxy.h"
+#include "ui/events/blink/input_handler_proxy_client.h"
+
+namespace blimp {
+class BlimpInputManager;
+
+// This class is created and lives on the compositor thread.

[nyquist, 2015/12/05 01:54:42]

What is it used for?
It owns a scoped_ptr to the InputHandlerProxy; so what's the difference between
a proxy and a wrapper?

Where does it get events from? Where does it send it back?

[Khushal, 2015/12/07 23:01:22]

Done.

+class BlimpInputHandlerWrapper : public ui::InputHandlerProxyClient {
+ public:
+  BlimpInputHandlerWrapper(
+      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+      const base::WeakPtr<BlimpInputManager> input_manager_weak_ptr,
+      cc::InputHandler* input_handler);
+
+  void HandleWebInputEvent(const blink::WebInputEvent& input_event);

[nyquist, 2015/12/05 01:54:42]

Who calls this? When should this be called? What is the expected output?

[Khushal, 2015/12/07 23:01:22]

Done.

+
+ private:
+  // InputHandlerProxyClient implementation.
+  void WillShutdown() override;
+  void TransferActiveWheelFlingAnimation(
+      const blink::WebActiveWheelFlingParameters& params) override;
+  blink::WebGestureCurve* CreateFlingAnimationCurve(
+      blink::WebGestureDevice device_source,
+      const blink::WebFloatPoint& velocity,
+      const blink::WebSize& cumulative_scroll) override;
+  void DidOverscroll(const gfx::Vector2dF& accumulated_overscroll,
+                     const gfx::Vector2dF& latest_overscroll_delta,
+                     const gfx::Vector2dF& current_fling_velocity,
+                     const gfx::PointF& causal_event_viewport_point) override;
+  void DidStopFlinging() override;
+  void DidAnimateForInput() override;
+
+  base::ThreadChecker compositor_thread_checker_;
+
+  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+
+  // Used to queue calls to the BlimpInputManager to be run on the main
+  // thread. This ensures that any tasks queued are abandoned after the
+  // BlimpInputManager is destroyed.
+  base::WeakPtr<BlimpInputManager> input_manager_weak_ptr_;
+
+  scoped_ptr<ui::InputHandlerProxy> input_handler_proxy_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlimpInputHandlerWrapper);
+};
+
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_INPUT_BLIMP_INPUT_HANDLER_WRAPPER_H_