Remaining bits to get views_examples_with_content_exe to work on Mac

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"
 
 #include "base/basictypes.h"
 #include "ui/native_theme/common_theme.h"
 
 namespace {
@@ skipping 18 matching lines @@
 
 SkColor NativeThemeMac::GetSystemColor(ColorId color_id) const {
   SkColor color;
   if (CommonThemeGetSystemColor(color_id, &color))
     return color;
 
   switch (color_id) {
     case kColorId_DialogBackground:
       return kDialogBackgroundColor;
     default:
-      NOTREACHED() << "Invalid color_id: " << color_id;
+      NOTIMPLEMENTED() << " Invalid color_id: " << color_id;
+      return FallbackTheme::GetSystemColor(color_id);
   }
 
   return kInvalidColorIdColor;
 }
 
 NativeThemeMac::NativeThemeMac() {
 }
 
 NativeThemeMac::~NativeThemeMac() {
 }
 
 }  // namespace ui