Makes KeyEvent struct traits restore Event::time_stamp() field

ui/events/event.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 "ui/events/event.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 
@@ skipping 1175 matching lines @@
   // Only Windows has native character events.
   if (is_char_)
     key_ = DomKey::FromCharacter(native_event.wParam);
   else
     key_ = PlatformKeyMap::DomKeyFromKeyboardCode(key_code(), flags());
 #endif
 }
 
 KeyEvent::KeyEvent(EventType type,
                    KeyboardCode key_code,
-                   int flags)
-    : Event(type, EventTimeForNow(), flags),
+                   int flags,
+                   base::TimeTicks time_stamp)
+    : Event(type,
+            time_stamp == base::TimeTicks() ? EventTimeForNow() : time_stamp,
+            flags),
       key_code_(key_code),
-      code_(UsLayoutKeyboardCodeToDomCode(key_code)) {
-}
+      code_(UsLayoutKeyboardCodeToDomCode(key_code)) {}
 
 KeyEvent::KeyEvent(EventType type,
                    KeyboardCode key_code,
                    DomCode code,
                    int flags)
     : Event(type, EventTimeForNow(), flags),
       key_code_(key_code),
       code_(code) {
 }
 
 KeyEvent::KeyEvent(EventType type,
                    KeyboardCode key_code,
                    DomCode code,
                    int flags,
                    DomKey key,
                    base::TimeTicks time_stamp)
     : Event(type, time_stamp, flags),
       key_code_(key_code),
       code_(code),
       key_(key) {}
 
-KeyEvent::KeyEvent(base::char16 character, KeyboardCode key_code, int flags)
-    : Event(ET_KEY_PRESSED, EventTimeForNow(), flags),
+KeyEvent::KeyEvent(base::char16 character,
+                   KeyboardCode key_code,
+                   int flags,
+                   base::TimeTicks time_stamp)
+    : Event(ET_KEY_PRESSED,
+            time_stamp == base::TimeTicks() ? EventTimeForNow() : time_stamp,
+            flags),
       key_code_(key_code),
       code_(DomCode::NONE),
       is_char_(true),
-      key_(DomKey::FromCharacter(character)) {
-}
+      key_(DomKey::FromCharacter(character)) {}
 
 KeyEvent::KeyEvent(const KeyEvent& rhs)
     : Event(rhs),
       key_code_(rhs.key_code_),
       code_(rhs.code_),
       is_char_(rhs.is_char_),
       key_(rhs.key_) {
 }
 
 KeyEvent& KeyEvent::operator=(const KeyEvent& rhs) {
@@ skipping 226 matching lines @@
                    flags | EF_FROM_TOUCH),
       details_(details),
       unique_touch_event_id_(unique_touch_event_id) {
   latency()->set_source_event_type(ui::SourceEventType::TOUCH);
 }
 
 GestureEvent::~GestureEvent() {
 }
 
 }  // namespace ui