Updates to skimage tool to use it for testing.

include/images/SkImageDecoder.h

Index: include/images/SkImageDecoder.h
diff --git a/include/images/SkImageDecoder.h b/include/images/SkImageDecoder.h
index 38e77f4df765e7139f0f2507f57fbd4e0c00ae23..54176bd9b98261eb191cab19b63baec96c08172a 100644
--- a/include/images/SkImageDecoder.h
+++ b/include/images/SkImageDecoder.h
@@ -26,7 +26,6 @@ class SkImageDecoder {
 public:
     virtual ~SkImageDecoder();
 
-    // Should be consistent with sFormatName
     enum Format {
         kUnknown_Format,
         kBMP_Format,
@@ -37,7 +36,7 @@ public:
         kWBMP_Format,
         kWEBP_Format,
 
-        kLastKnownFormat = kWEBP_Format
+        kLastKnownFormat = kWEBP_Format,
     };
 
     /** Return the format of image this decoder can decode. If this decoder can decode multiple
@@ -45,6 +44,11 @@ public:
     */
     virtual Format getFormat() const;
 
+    /** Return the format of the SkStream or kUnknown_Format if it cannot be determined. Rewinds the
+        stream before returning.
+    */
+    static Format GetStreamFormat(SkStream*);
+
     /** Return a readable string of the value returned by getFormat().
     */
     const char* getFormatName() const;
@@ -416,13 +420,6 @@ private:
     mutable bool            fShouldCancelDecode;
     bool                    fPreferQualityOverSpeed;
 
-    /** Contains the image format name.
-     *  This should be consistent with Format.
-     *
-     *  The format name gives a more meaningful error message than enum.
-     */
-    static const char* sFormatName[];
-
     // illegal
     SkImageDecoder(const SkImageDecoder&);
     SkImageDecoder& operator=(const SkImageDecoder&);