[DevTools] Interactive test for DevTools touch emulation.

ui/events/gesture_detection/gesture_provider.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 "ui/events/gesture_detection/gesture_provider.h"
 
 #include <cmath>
 
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
@@ skipping 533 matching lines @@
   InitGestureDetectors(config);
 }
 
 GestureProvider::~GestureProvider() {}
 
 bool GestureProvider::OnTouchEvent(const MotionEvent& event) {
   TRACE_EVENT1("input", "GestureProvider::OnTouchEvent",
                "action", GetMotionEventActionName(event.GetAction()));
 
   DCHECK_NE(0u, event.GetPointerCount());
+  DCHECK(!event.GetEventTime().is_null());
 
   if (!CanHandle(event))
     return false;
 
   const bool in_scale_gesture =
       scale_gesture_listener_->IsScaleGestureDetectionInProgress();
 
   OnTouchEventHandlingBegin(event);
   gesture_listener_->OnTouchEvent(event, in_scale_gesture);
   scale_gesture_listener_->OnTouchEvent(event);
@@ skipping 211 matching lines @@
   if (current_down_event_)
     return;
 
   const bool double_tap_enabled = double_tap_support_for_page_ &&
                                   double_tap_support_for_platform_;
   gesture_listener_->SetDoubleTapEnabled(double_tap_enabled);
   scale_gesture_listener_->SetDoubleTapEnabled(double_tap_enabled);
 }
 
 }  //  namespace ui