Minor cleanups in picture_utils header file.

tools/picture_utils.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef picture_utils_DEFINED
 #define picture_utils_DEFINED
 
-#include "SkTypes.h"
-
 class SkBitmap;
-class SkFILEStream;
-class SkPicture;
 class SkString;
 
 namespace sk_tools {
     // since PNG insists on unpremultiplying our alpha, we take no precision
     // chances and force all pixels to be 100% opaque, otherwise on compare we
     // may not get a perfect match.
     //
     // This expects a bitmap with a config type of 8888 and for the pixels to
     // not be on the GPU.
     void force_all_opaque(const SkBitmap& bitmap);
@@ skipping 25 matching lines @@
      * @param baseName last part of the filename
      *
      * @return true if written out successfully
      */
     bool write_bitmap_to_disk(const SkBitmap& bm, const SkString& dirPath,
                               const char *subdirOrNull, const SkString& baseName);
 
 } // namespace sk_tools
 
 #endif  // picture_utils_DEFINED