Decouple EventWithLatencyInfo and WebInputEventTraits [extern templates]

content/browser/renderer_host/input/render_widget_host_latency_tracker.cc

 // Copyright 2014 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.
 
 #include "content/browser/renderer_host/input/render_widget_host_latency_tracker.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "build/build_config.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
+#include "content/common/input/web_input_event_traits.h"
 
 using blink::WebGestureEvent;
 using blink::WebInputEvent;
 using blink::WebMouseEvent;
 using blink::WebMouseWheelEvent;
 using blink::WebTouchEvent;
 using ui::LatencyInfo;
 
 namespace content {
 namespace {
@@ skipping 545 matching lines @@
                            latency_component_id_, nullptr)) {
     return;
   }
 
   ComputeScrollLatencyHistograms(gpu_swap_begin_component,
                                  gpu_swap_end_component, latency_component_id_,
                                  latency);
 }
 
 }  // namespace content