Add touch drag UMA latency metric.

content/browser/renderer_host/input/input_router_impl.h

 // Copyright 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_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_
 
 #include <stdint.h>
 
 #include <queue>
@@ skipping 95 matching lines @@
       const MouseWheelEventWithLatencyInfo& touch_event) override;
   void OnMouseWheelEventAck(const MouseWheelEventWithLatencyInfo& event,
                             InputEventAckState ack_result) override;
 
   bool SendMoveCaret(scoped_ptr<IPC::Message> message);
   bool SendSelectMessage(scoped_ptr<IPC::Message> message);
   bool Send(IPC::Message* message);
 
   // Filters and forwards |input_event| to the appropriate handler.
   void FilterAndSendWebInputEvent(const blink::WebInputEvent& input_event,
-                                  const ui::LatencyInfo& latency_info);
+                                  ui::LatencyInfo* latency_info);
 
   // Utility routine for filtering and forwarding |input_event| to the
   // appropriate handler. |input_event| will be offered to the overscroll
   // controller, client and renderer, in that order.
   void OfferToHandlers(const blink::WebInputEvent& input_event,
-                       const ui::LatencyInfo& latency_info);
+                       ui::LatencyInfo* latency_info);
 
   // Returns true if |input_event| was consumed by the client.
   bool OfferToClient(const blink::WebInputEvent& input_event,
                      const ui::LatencyInfo& latency_info);
 
   // Returns true if |input_event| was successfully sent to the renderer
   // as an async IPC Message.
   bool OfferToRenderer(const blink::WebInputEvent& input_event,
-                       const ui::LatencyInfo& latency_info,
-                       InputEventDispatchType dispatch_type);
+                       InputEventDispatchType dispatch_type,
+                       ui::LatencyInfo* latency_info);
 
   // IPC message handlers
   void OnInputEventAck(const InputEventAck& ack);
   void OnDidOverscroll(const DidOverscrollParams& params);
   void OnMsgMoveCaretAck();
   void OnSelectMessageAck();
   void OnHasTouchEventHandlers(bool has_handlers);
   void OnSetTouchAction(TouchAction touch_action);
   void OnDidStopFlinging();
 
@@ skipping 112 matching lines @@
   InputEventStreamValidator output_stream_validator_;
 
   float device_scale_factor_;
 
   DISALLOW_COPY_AND_ASSIGN(InputRouterImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_