Move simple png encoding for image_diff into tools/

tools/imagediff/image_diff_png.h

Index: tools/imagediff/image_diff_png.h
diff --git a/webkit/support/webkit_support_gfx.h b/tools/imagediff/image_diff_png.h
similarity index 62%
rename from webkit/support/webkit_support_gfx.h
rename to tools/imagediff/image_diff_png.h
index f78f8c5726603071e17da3bef672d81d889f1ad0..2e6b155f774e4fd9c0ce3f65fca05a401ded16a7 100644
--- a/webkit/support/webkit_support_gfx.h
+++ b/tools/imagediff/image_diff_png.h
@@ -2,13 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef WEBKIT_SUPPORT_WEBKIT_SUPPORT_GFX_H_
-#define WEBKIT_SUPPORT_WEBKIT_SUPPORT_GFX_H_
+#ifndef TOOLS_IMAGEDIFF_IMAGE_DIFF_PNG_H_
+#define TOOLS_IMAGEDIFF_IMAGE_DIFF_PNG_H_
 
 #include <string>
 #include <vector>
 
-namespace webkit_support {
+namespace image_diff_png {
 
 // Decode a PNG into an RGBA pixel array.
 bool DecodePNG(const unsigned char* input, size_t input_size,
@@ -30,14 +30,6 @@ bool EncodeBGRAPNG(const unsigned char* input,
                    bool discard_transparency,
                    std::vector<unsigned char>* output);
 
-bool EncodeBGRAPNGWithChecksum(const unsigned char* input,
-                               int width,
-                               int height,
-                               int row_byte_width,
-                               bool discard_transparency,
-                               const std::string& checksum,
-                               std::vector<unsigned char>* output);
+}  // namespace image_diff_png
 
-}  // namespace webkit_support
-
-#endif  // WEBKIT_SUPPORT_WEBKIT_SUPPORT_GFX_H_
+#endif  // TOOLS_IMAGEDIFF_IMAGE_DIFF_PNG_H_