Adds an iOS implementation of gfx::Image.

ui/gfx/image/image_util.h

Index: ui/gfx/image/image_util.h
diff --git a/ui/gfx/image/image_util.h b/ui/gfx/image/image_util.h
index 06643172c9cfc029121bff33426992c402de2cef..67670626dc38eadf2b5990802350165efef3d7c8 100644
--- a/ui/gfx/image/image_util.h
+++ b/ui/gfx/image/image_util.h
@@ -21,17 +21,17 @@ namespace gfx {
 UI_EXPORT Image* ImageFromPNGEncodedData(const unsigned char* input,
                                          size_t input_size);
 
+// Fills the |dst| vector with PNG-encoded bytes based on the given Image.
+// Returns true if the Image was encoded successfully.
+UI_EXPORT bool PNGEncodedDataFromImage(const Image& image,
+                                       std::vector<unsigned char>* dst);
+
 // Creates an image from the given JPEG-encoded input.  The caller owns the
 // returned Image.  If there was an error creating the image, returns an
 // IsEmpty() Image.
 UI_EXPORT Image ImageFromJPEGEncodedData(const unsigned char* input,
                                          size_t input_size);
 
-// Fills the |dst| vector with PNG-encoded bytes based on the given Image.
-// Returns true if the Image was encoded successfully.
-UI_EXPORT bool PNGEncodedDataFromImage(const Image& image,
-                                       std::vector<unsigned char>* dst);
-
 // Fills the |dst| vector with JPEG-encoded bytes based on the given Image.
 // |quality| determines the compression level, 0 == lowest, 100 == highest.
 // Returns true if the Image was encoded successfully.