Refactor the PlatformContext layer to have only one class.

chrome/browser/views/theme_helpers.cc

 // Copyright (c) 2006-2008 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 "chrome/browser/views/theme_helpers.h"
 
 #include <atlbase.h>
 #include <atlapp.h>
 #include <atltheme.h>
 
@@ skipping 46 matching lines @@
     // the gradient.
     gradient_shader->unref();
     paint.setStyle(SkPaint::kFill_Style);
     canvas.drawRectCoords(SkIntToScalar(0), SkIntToScalar(0),
                           SkIntToScalar(width), SkIntToScalar(1), paint);
   }
 
   // Extract the color values from the selected pixels
   // The | in the following operations forces the alpha to 0xFF. This is
   // needed as windows sets the alpha to 0 when it renders.
-  skia::BitmapPlatformDeviceWin& device =
-      static_cast<skia::BitmapPlatformDeviceWin&>(
+  skia::BitmapPlatformDevice& device =
+      static_cast<skia::BitmapPlatformDevice&>(
           canvas.getTopPlatformDevice());
   *c1 = 0xFF000000 | device.getColorAt(x1, 0);
   *c2 = 0xFF000000 | device.getColorAt(x2, 0);
 }
 
 void GetDarkLineColor(SkColor* dark_color) {
   DCHECK(dark_color) << "ThemeHelpers::DarkColor - dark_color is NULL!";
 
   CTheme theme;
   if (theme.IsThemingSupported())
     theme.OpenThemeData(NULL, L"REBAR");
 
   // Note: the alpha values were chosen scientifically according to what looked
   //       best to me at the time! --beng
   if (!theme.IsThemeNull()) {
     *dark_color = SkColorSetARGB(60, 0, 0, 0);
   } else {
     COLORREF shadow_ref = ::GetSysColor(COLOR_3DSHADOW);
     *dark_color = SkColorSetARGB(175,
                                  GetRValue(shadow_ref),
                                  GetGValue(shadow_ref),
                                  GetBValue(shadow_ref));
   }
 }