Validate that ui::Event::time_stamp comes from the same clock as TimeTicks::Now

ui/events/win/events_win.cc

 // Copyright (c) 2012 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 <stdint.h>
 #include <windowsx.h>
 
 #include "ui/events/event_constants.h"
 
 #include "base/logging.h"
@@ skipping 206 matching lines @@
 
 base::TimeTicks EventTimeFromNative(const base::NativeEvent& native_event) {
   // On Windows, the native input event timestamp (|native_event.time|) is
   // coming from |GetTickCount()| clock [1], while in platform independent code
   // path we get timestamps by calling |TimeTicks::Now()|, which, if using high-
   // resolution timer as underlying implementation, could have different time
   // origin than |GetTickCount()|. To avoid the mismatching, we use
   // |TimeTicks::Now()| for event timestamp instead of the native timestamp to
   // ensure computed input latency and web exposed timestamp is consistent with
   // other components.
+  // It is unnecessary to invoke |ValidateEventTimeClock| here because of above.
   // [1] http://blogs.msdn.com/b/oldnewthing/archive/2014/01/22/10491576.aspx
   return EventTimeForNow();
 }
 
 gfx::Point EventLocationFromNative(const base::NativeEvent& native_event) {
   POINT native_point;
   if ((native_event.message == WM_MOUSELEAVE ||
        native_event.message == WM_NCMOUSELEAVE) ||
       IsScrollEvent(native_event)) {
     // These events have no coordinates. For sanity with rest of events grab
@@ skipping 176 matching lines @@
 }
 
 LPARAM GetLParamFromScanCode(uint16_t scan_code) {
   LPARAM l_param = static_cast<LPARAM>(scan_code & 0x00FF) << 16;
   if ((scan_code & 0xE000) == 0xE000)
     l_param |= (1 << 24);
   return l_param;
 }
 
 }  // namespace ui