Add id properties to PointerEvent

ui/events/cocoa/events_mac.mm

 // 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/event_utils.h"
 
 #include <Cocoa/Cocoa.h>
 #include <stdint.h>
 
 #include "base/logging.h"
@@ skipping 117 matching lines @@
     case NSOtherMouseDragged:
       return EF_MIDDLE_MOUSE_BUTTON;
     default:
       break;
   }
   return 0;
 }
 
 PointerDetails GetMousePointerDetailsFromNative(
     const base::NativeEvent& native_event) {
-  return PointerDetails(EventPointerType::POINTER_TYPE_MOUSE);
+  return PointerDetails(EventPointerType::POINTER_TYPE_MOUSE,
+                        PointerEvent::kMousePointerId);
 }
 
 gfx::Vector2d GetMouseWheelOffset(const base::NativeEvent& event) {
   if ([event hasPreciseScrollingDeltas]) {
     // Handle continuous scrolling devices such as a Magic Mouse or a trackpad.
     // -scrollingDelta{X|Y} have float return types but they return values that
     // are already rounded to integers.
     // The values are the same as the values returned from calling
     // CGEventGetIntegerValueField(kCGScrollWheelEventPointDeltaAxis{1|2}).
     return gfx::Vector2d([event scrollingDeltaX], [event scrollingDeltaY]);
@@ skipping 150 matching lines @@
   uint16_t return_value;
   [text getCharacters:&return_value];
   return return_value;
 }
 
 bool IsCharFromNative(const base::NativeEvent& native_event) {
   return false;
 }
 
 }  // namespace ui