First pass at removal of unneeded dependencies on skia\ext\platform_canvas.h

ui/gfx/native_theme.h

 // Copyright (c) 2011 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.
 
 #ifndef UI_GFX_NATIVE_THEME_H_
 #define UI_GFX_NATIVE_THEME_H_
 #pragma once
 
-#include "skia/ext/platform_canvas.h"
+#include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/ui_api.h"
 
+class SkCanvas;
+
 namespace gfx {
 
 class Rect;
 class Size;
 
 // This class supports drawing UI controls (like buttons, text fields, lists,
 // comboboxes, etc) that look like the native UI controls of the underlying
 // platform, such as Windows or Linux.
 //
 // The supported control types are listed in the Part enum.  These parts can be
@@ skipping 199 matching lines @@
   static unsigned int thumb_inactive_color_;
   static unsigned int thumb_active_color_;
   static unsigned int track_color_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeTheme);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_NATIVE_THEME_H_