Add imgblur tool to assist BlurMaskFilter debugging

tools/sk_tool_utils.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef sk_tool_utils_DEFINED
 #define sk_tool_utils_DEFINED
 
@@ skipping 117 matching lines @@
     void add_to_text_blob(SkTextBlobBuilder* builder, const char* text, const SkPaint& origPaint,
                           SkScalar x, SkScalar y);
 
     void create_hemi_normal_map(SkBitmap* bm, const SkIRect& dst);
 
     void create_frustum_normal_map(SkBitmap* bm, const SkIRect& dst);
 
     void create_tetra_normal_map(SkBitmap* bm, const SkIRect& dst);
 
     void make_big_path(SkPath& path);
+
+    // Return a blurred version of 'src'. This doesn't use a separable filter
+    // so it is slow!
+    SkBitmap slow_blur(const SkBitmap& src, float sigma);
+
 }  // namespace sk_tool_utils
 
 #endif  // sk_tool_utils_DEFINED