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

ui/views/controls/menu/menu_scroll_view_container.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/views/controls/menu/menu_scroll_view_container.h"
 
 #include "base/macros.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "ui/accessibility/ax_view_state.h"
@@ skipping 57 matching lines @@
 
   int OnPerformDrop(const ui::DropTargetEvent& event) override {
     return ui::DragDropTypes::DRAG_NONE;
   }
 
   void OnPaint(gfx::Canvas* canvas) override {
     const MenuConfig& config = MenuConfig::instance();
 
     // The background.
     gfx::Rect item_bounds(0, 0, width(), height());
-    NativeTheme::ExtraParams extra;
-    extra.menu_item.is_selected = false;
+    NativeTheme::ExtraParams extra = NativeTheme::ExtraParams();
     GetNativeTheme()->Paint(canvas->sk_canvas(),
                             NativeTheme::kMenuItemBackground,
                             NativeTheme::kNormal, item_bounds, extra);
 
     // Then the arrow.
     int x = width() / 2;
     int y = (height() - config.scroll_arrow_height) / 2;
 
     int x_left = x - config.scroll_arrow_height;
     int x_right = x + config.scroll_arrow_height;
@@ skipping 232 matching lines @@
     case MENU_ANCHOR_BUBBLE_ABOVE:
       return BubbleBorder::BOTTOM_CENTER;
     case MENU_ANCHOR_BUBBLE_BELOW:
       return BubbleBorder::TOP_CENTER;
     default:
       return BubbleBorder::NONE;
   }
 }
 
 }  // namespace views