Rejigger ThemeService: move exposure of ThemeProvider interface to a

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #include <cmath>
 #include <limits>
@@ skipping 2340 matching lines @@
 
 - (TabMediaState)mediaStateForContents:(content::WebContents*)contents {
   return chrome::GetTabMediaStateForContents(contents);
 }
 
 - (void)themeDidChangeNotification:(NSNotification*)notification {
   [self setNewTabImages];
 }
 
 - (void)setNewTabImages {
-  ThemeService *theme =
-      static_cast<ThemeService*>([[tabStripView_ window] themeProvider]);
+  ui::ThemeProvider* theme = [[tabStripView_ window] themeProvider];
   if (!theme)
     return;
 
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   NSImage* mask = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON_MASK).ToNSImage();
   NSImage* normal = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON).ToNSImage();
   NSImage* hover = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON_H).ToNSImage();
   NSImage* pressed = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON_P).ToNSImage();
 
   NSImage* foreground = ApplyMask(
       theme->GetNSImageNamed(IDR_THEME_TAB_BACKGROUND), mask);
 
   [[newTabButton_ cell] setImage:Overlay(foreground, normal, 1.0)
                   forButtonState:image_button_cell::kDefaultState];
   [[newTabButton_ cell] setImage:Overlay(foreground, hover, 1.0)
                   forButtonState:image_button_cell::kHoverState];
   [[newTabButton_ cell] setImage:Overlay(foreground, pressed, 1.0)
                     forButtonState:image_button_cell::kPressedState];
 
   // IDR_THEME_TAB_BACKGROUND_INACTIVE is only used with the default theme.
-  if (theme->UsingDefaultTheme()) {
+  if (theme->UsingSystemTheme()) {
     const CGFloat alpha = tabs::kImageNoFocusAlpha;
     NSImage* background = ApplyMask(
         theme->GetNSImageNamed(IDR_THEME_TAB_BACKGROUND_INACTIVE), mask);
     [[newTabButton_ cell] setImage:Overlay(background, normal, alpha)
                     forButtonState:image_button_cell::kDefaultStateBackground];
     [[newTabButton_ cell] setImage:Overlay(background, hover, alpha)
                     forButtonState:image_button_cell::kHoverStateBackground];
   } else {
     [[newTabButton_ cell] setImage:nil
                     forButtonState:image_button_cell::kDefaultStateBackground];
     [[newTabButton_ cell] setImage:nil
                     forButtonState:image_button_cell::kHoverStateBackground];
   }
 }
 
 @end