Allow the Mac theme provider to give default colors/tints if requested.

app/theme_provider.h

 // Copyright (c) 2009 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 APP_THEME_PROVIDER_H_
 #define APP_THEME_PROVIDER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 53 matching lines @@
 
   // Reads the image data from the theme file into the specified vector. Only
   // valid for un-themed resources and the themed IDR_THEME_NTP_* in most
   // implementations of ThemeProvider. Returns NULL on error.
   virtual RefCountedMemory* GetRawData(int id) const = 0;
 
 #if defined(OS_MACOSX)
   // Gets the NSImage with the specified |id|.
   //
   // The bitmap is not assumed to exist. If a theme does not provide an image,
+  // if |allow_default| is true, then the default image will be returned, else
   // this function will return nil.
-  virtual NSImage* GetNSImageNamed(int id) const = 0;
+  virtual NSImage* GetNSImageNamed(int id, bool allow_default) const = 0;
 
   // Gets the NSColor with the specified |id|.
   //
-  // The color is not assumed to exist. If a theme does not provide an color,
-  // this function will return nil.
-  virtual NSColor* GetNSColor(int id) const = 0;
+  // The color is not assumed to exist. If a theme does not provide an color, if
+  // |allow_default| is true, then the default color will be returned, else this
+  // function will return nil.
+  virtual NSColor* GetNSColor(int id, bool allow_default) const = 0;
 
   // Gets the NSColor for tinting with the specified |id|.
   //
   // The tint is not assumed to exist. If a theme does not provide a tint with
-  // that id, this function will return nil.
-  virtual NSColor* GetNSColorTint(int id) const = 0;
+  // that id, if |allow_default| is true, then the default tint will be
+  // returned, else this function will return nil.
+  virtual NSColor* GetNSColorTint(int id, bool allow_default) const = 0;
 #elif defined(OS_POSIX) && !defined(TOOLKIT_VIEWS)
   // Gets the GdkPixbuf with the specified |id|.  Returns a pointer to a shared
   // instance of the GdkPixbuf.  This shared GdkPixbuf is owned by the theme
   // provider and should not be freed.
   //
   // The bitmap is assumed to exist. This function will log in release, and
   // assert in debug mode if it does not. On failure, this will return a
   // pointer to a shared empty placeholder bitmap so it will be visible what
   // is missing.
   virtual GdkPixbuf* GetPixbufNamed(int id) const = 0;
 
   // As above, but flips it in RTL locales.
   virtual GdkPixbuf* GetRTLEnabledPixbufNamed(int id) const = 0;
 #endif
 };
 
 #endif  // APP_THEME_PROVIDER_H_