Move compositor thread input handling logic into content

content/renderer/gpu/input_handler_proxy_client.h

+// Copyright (c) 2013 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 CONTENT_RENDERER_GPU_INPUT_HANDLER_PROXY_CLIENT_H_
+#define CONTENT_RENDERER_GPU_INPUT_HANDLER_PROXY_CLIENT_H_
+
+namespace WebKit {
+class WebGestureCurve;
+struct WebActiveWheelFlingParameters;
+struct WebFloatPoint;
+struct WebSize;
+}
+
+namespace content {
+
+class InputHandlerProxyClient {
+ public:
+  // Callbacks invoked from the compositor thread.

[danakj, 2013/05/06 16:33:39]

This comment is placed like it only refers to one function, but I think it
refers to everything. Should this be a class-level comment?

Then WillShutdown could get something more descriptive of its purpose.

+  virtual void WillShutdown() = 0;
+
+  // Exactly one of the following two callbacks will be invoked after every
+  // call to InputHandlerClientImpl::handleInputEvent():

[danakj, 2013/05/06 16:33:39]

IHProxy::/H/andleInputEvent

+
+  // Called when the InputHandlerClientImpl handled the input event and no

[danakj, 2013/05/06 16:33:39]

IHProxy throughout this file's comments

+  // further processing is required.
+  virtual void DidHandleInputEvent() = 0;
+
+  // Called when the InputHandlerClientImpl did not handle the input event.
+  // If send_to_widget is true, the input event should be forwarded to the
+  // WebWidget associated with this compositor for further processing.
+  virtual void DidNotHandleInputEvent(bool send_to_widget) = 0;
+
+  // Transfers an active wheel fling animation initiated by a previously
+  // handled input event out to the client.
+  virtual void TransferActiveWheelFlingAnimation(
+      const WebKit::WebActiveWheelFlingParameters& params) = 0;
+
+  // Creates a new fling animation curve instance for device |device_source|
+  // with |velocity| and already scrolled |cumulative_scroll| pixels.
+  virtual WebKit::WebGestureCurve* CreateFlingAnimationCurve(
+      int device_source,
+      const WebKit::WebFloatPoint& velocity,
+      const WebKit::WebSize& cumulative_scroll) = 0;
+
+ protected:
+  virtual ~InputHandlerProxyClient() {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_GPU_INPUT_HANDLER_PROXY_CLIENT_H_