Use correct timestamp for generated mouse events on Mac.

content/browser/renderer_host/render_widget_host_view_mac.mm

 // 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 "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <Carbon/Carbon.h>
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
@@ skipping 1149 matching lines @@
 
   // Create a fake mouse event to inform the render widget that the mouse
   // left or entered.
   NSWindow* window = [cocoa_view_ window];
   // TODO(asvitkine): If the location outside of the event stream doesn't
   // correspond to the current event (due to delayed event processing), then
   // this may result in a cursor flicker if there are later mouse move events
   // in the pipeline. Find a way to use the mouse location from the event that
   // dismissed the context menu.
   NSPoint location = [window mouseLocationOutsideOfEventStream];
+  NSTimeInterval event_time = [[NSApp currentEvent] timestamp];
   NSEvent* event = [NSEvent mouseEventWithType:NSMouseMoved
                                       location:location
                                  modifierFlags:0
-                                     timestamp:0
+                                     timestamp:event_time
                                   windowNumber:window_number()
                                        context:nil
                                    eventNumber:0
                                     clickCount:0
                                       pressure:0];
   WebMouseEvent web_event = WebMouseEventBuilder::Build(event, cocoa_view_);
   if (showing)
     web_event.setType(WebInputEvent::MouseLeave);
   ForwardMouseEvent(web_event);
 }
@@ skipping 2270 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end