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

ui/native_theme/common_theme.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/native_theme/common_theme.h"
 
 #include "base/logging.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 442 matching lines @@
   canvas->drawLine(position_x, rect.y(), position_x, rect.bottom(), paint);
 }
 
 void CommonThemePaintMenuBackground(SkCanvas* canvas, const gfx::Rect& rect) {
   SkPaint paint;
   paint.setColor(
       GetAuraColor(NativeTheme::kColorId_MenuBackgroundColor, nullptr));
   canvas->drawRect(gfx::RectToSkRect(rect), paint);
 }
 
-void CommonThemePaintMenuItemBackground(SkCanvas* canvas,
-                                        NativeTheme::State state,
-                                        const gfx::Rect& rect) {
+void CommonThemePaintMenuItemBackground(
+    SkCanvas* canvas,
+    NativeTheme::State state,
+    const gfx::Rect& rect,
+    const NativeTheme::MenuItemExtraParams& menu_item) {
   SkPaint paint;
   switch (state) {
     case NativeTheme::kNormal:
     case NativeTheme::kDisabled:
       paint.setColor(
           GetAuraColor(NativeTheme::kColorId_MenuBackgroundColor, nullptr));
       break;
     case NativeTheme::kHovered:
       paint.setColor(GetAuraColor(
           NativeTheme::kColorId_FocusedMenuItemBackgroundColor, nullptr));
       break;
     default:
       NOTREACHED() << "Invalid state " << state;
       break;
   }
+  if (menu_item.corner_radius > 0) {
+    const SkScalar radius = SkIntToScalar(menu_item.corner_radius);
+    canvas->drawRoundRect(gfx::RectToSkRect(rect), radius, radius, paint);
+    return;
+  }
   canvas->drawRect(gfx::RectToSkRect(rect), paint);
 }
 
 // static
 scoped_ptr<gfx::Canvas> CommonThemeCreateCanvas(SkCanvas* sk_canvas) {
   // TODO(pkotwicz): Do something better and don't infer device
   // scale factor from canvas scale.
   SkMatrix m = sk_canvas->getTotalMatrix();
   float device_scale = static_cast<float>(SkScalarAbs(m.getScaleX()));
   return make_scoped_ptr(new gfx::Canvas(skia::SharePtr(sk_canvas),
                                          device_scale));
 }
 
 }  // namespace ui