[Extensions Toolbar Mac] Allow the overflow toolbar to use the theme provider

chrome/browser/ui/cocoa/image_button_cell.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/image_button_cell.h"
 
 #include "base/logging.h"
 #import "chrome/browser/themes/theme_service.h"
 #import "chrome/browser/ui/cocoa/rect_path_utils.h"
 #import "chrome/browser/ui/cocoa/themed_window.h"
@@ skipping 114 matching lines @@
   image_[state].image.reset([image retain]);
   image_[state].imageId = 0;
   [[self controlView] setNeedsDisplay:YES];
 }
 
 - (CGFloat)imageAlphaForWindowState:(NSWindow*)window {
   BOOL windowHasFocus = [window isMainWindow] || [window isKeyWindow];
   return windowHasFocus ? 1.0 : kImageNoFocusAlpha;
 }
 
+- (ui::ThemeProvider*)themeProviderForWindow:(NSWindow*)window {
+  return [window themeProvider];
+}
+
 - (void)drawFocusRingWithFrame:(NSRect)cellFrame inView:(NSView*)controlView {
   if (![self showsFirstResponder])
     return;
   gfx::ScopedNSGraphicsContextSaveGState scoped_state;
   const CGFloat lineWidth = [controlView cr_lineWidth];
   rect_path_utils::FrameRectWithInset(rect_path_utils::RoundedCornerAll,
                                       NSInsetRect(cellFrame, 0, lineWidth),
                                       0.0,            // insetX
                                       0.0,            // insetY
                                       3.0,            // outerRadius
@@ skipping 14 matching lines @@
   if ([self isMouseInside] && has(image_button_cell::kHoverState))
     return image_button_cell::kHoverState;
   return image_button_cell::kDefaultState;
 }
 
 - (NSImage*)imageForID:(NSInteger)imageID
            controlView:(NSView*)controlView {
   if (!imageID)
     return nil;
 
-  ui::ThemeProvider* themeProvider = [[controlView window] themeProvider];
+  ui::ThemeProvider* themeProvider =
+      [self themeProviderForWindow:[controlView window]];
   if (!themeProvider)
     return nil;
 
   return themeProvider->GetNSImageNamed(imageID);
 }
 
 - (void)setIsMouseInside:(BOOL)isMouseInside {
   if (isMouseInside_ != isMouseInside) {
     isMouseInside_ = isMouseInside;
     NSView<ImageButton>* control =
@@ skipping 17 matching lines @@
 
 - (void)mouseEntered:(NSEvent*)theEvent {
   [self setIsMouseInside:YES];
 }
 
 - (void)mouseExited:(NSEvent*)theEvent {
   [self setIsMouseInside:NO];
 }
 
 @end