Touch emulator: overwrite timestamps from mouse event with current time.

content/browser/renderer_host/input/touch_emulator.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/touch_emulator.h"
 
 #include "content/browser/renderer_host/input/motion_event_web.h"
 #include "content/browser/renderer_host/input/web_input_event_util.h"
 #include "content/common/input/web_touch_event_traits.h"
 #include "content/public/common/content_client.h"
@@ skipping 298 matching lines @@
 }
 
 void TouchEmulator::PinchEnd(const WebGestureEvent& event) {
   DCHECK(pinch_gesture_active_);
   pinch_gesture_active_ = false;
   FillPinchEvent(event);
   pinch_event_.type = WebInputEvent::GesturePinchEnd;
   client_->ForwardGestureEvent(pinch_event_);
 }
 
 void TouchEmulator::FillPinchEvent(const WebInputEvent& event) {

[jdduke (slow), 2014/04/25 16:56:05]

Could you make this |const WebGestureEvent& event) ? Just want it to be clear
we're getting timestamps from "valid" sources at all times.

[dgozman, 2014/04/28 09:34:21]

Done.

   pinch_event_.timeStampSeconds = event.timeStampSeconds;
   pinch_event_.modifiers = event.modifiers;
   pinch_event_.sourceDevice = blink::WebGestureEvent::Touchscreen;
   pinch_event_.x = pinch_anchor_.x();
   pinch_event_.y = pinch_anchor_.y();
 }
 
 void TouchEmulator::ScrollEnd(const WebGestureEvent& event) {
   WebGestureEvent scroll_event;
   scroll_event.timeStampSeconds = event.timeStampSeconds;
@@ skipping 24 matching lines @@
       break;
     default:
       eventType = WebInputEvent::Undefined;
       NOTREACHED();
   }
   touch_event_.touchesLength = 1;
   touch_event_.modifiers = mouse_event.modifiers;
   WebTouchEventTraits::ResetTypeAndTouchStates(
       eventType, mouse_event.timeStampSeconds, &touch_event_);
 
+  // On some platforms mouse event's timestamp does not necessarily relate to
+  // the system time at all, so use base::TimeTicks::HighResNow() if possible,
+  // or base::TimeTicks::Now() otherwise.
+  base::TimeTicks now;
+  if (base::TimeTicks::IsHighResNowFastAndReliable())
+    now = base::TimeTicks::HighResNow();
+  else
+    now = base::TimeTicks::Now();
+  touch_event_.timeStampSeconds = (now - base::TimeTicks()).InSecondsF();
+
   WebTouchPoint& point = touch_event_.touches[0];
   point.id = 0;
   point.radiusX = point.radiusY = 1.f;
   point.force = 1.f;
   point.rotationAngle = 0.f;
   point.position.x = mouse_event.x;
   point.screenPosition.x = mouse_event.globalX;
   point.position.y = mouse_event.y;
   point.screenPosition.y = mouse_event.globalY;
 
   return true;
 }
 
 bool TouchEmulator::InPinchGestureMode() const {
   return shift_pressed_ && allow_pinch_;
 }
 
 }  // namespace content