Move normal map creation methods to sk_tools

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 101 matching lines @@
                                size_t rowBytes) override {
             return SkImageEncoder::EncodeData(info, pixels, rowBytes,
                                               SkImageEncoder::kPNG_Type, 100);
         }
     };
 
     // A helper for inserting a drawtext call into a SkTextBlobBuilder
     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);
+
 }  // namespace sk_tool_utils
 
 #endif  // sk_tool_utils_DEFINED