Enables hot-tracking for overflow extension buttons in the app menu

ui/native_theme/native_theme_mac.mm

 // Copyright (c) 2013 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/native_theme/native_theme_mac.h"
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
 #include "base/mac/mac_util.h"
@@ skipping 366 matching lines @@
     paint.setColor(kMenuPopupBackgroundColor);
   const SkScalar radius = SkIntToScalar(menu_background.corner_radius);
   SkRect rect = gfx::RectToSkRect(gfx::Rect(size));
   canvas->drawRoundRect(rect, radius, radius, paint);
 }
 
 void NativeThemeMac::PaintMenuItemBackground(
     SkCanvas* canvas,
     State state,
     const gfx::Rect& rect,
-    const MenuListExtraParams& menu_list) const {
+    const MenuItemExtraParams& menu_item) const {
   SkPaint paint;
   switch (state) {
     case NativeTheme::kNormal:
     case NativeTheme::kDisabled:
       // Draw nothing over the regular background.
       break;
     case NativeTheme::kHovered:
       // TODO(tapted): Draw a gradient, and use [NSColor currentControlTint] to
       // pick colors. The System color "selectedMenuItemColor" is actually still
       // blue for Graphite. And while "keyboardFocusIndicatorColor" does change,
@@ skipping 11 matching lines @@
   set_scrollbar_button_length(0);
   SetScrollbarColors(kScrollerThumbColor,
                      kScrollerThumbHoverColor,
                      kScrollerTrackGradientColors[0]);
 }
 
 NativeThemeMac::~NativeThemeMac() {
 }
 
 }  // namespace ui