remove getter for imagegenerator factory, update test

include/core/SkGraphics.h

Index: include/core/SkGraphics.h
diff --git a/include/core/SkGraphics.h b/include/core/SkGraphics.h
index e552633d5f3df3aa32c8532f1aaf1bef8ef4d259..f2e3d8dac04479fb9f50965345621e78f998c079 100644
--- a/include/core/SkGraphics.h
+++ b/include/core/SkGraphics.h
@@ -150,9 +150,11 @@ public:
      *  To instantiate images from encoded data, first looks at this runtime function-ptr. If it
      *  exists, it is called to create an SkImageGenerator from SkData. If there is no function-ptr
      *  or there is, but it returns NULL, then skia will call its internal default implementation.
+     *
+     *  Returns the previous factory (which could be NULL).
      */
-    static ImageGeneratorFromEncodedFactory GetImageGeneratorFromEncodedFactory();
-    static void SetImageGeneratorFromEncodedFactory(ImageGeneratorFromEncodedFactory);
+    static ImageGeneratorFromEncodedFactory
+           SetImageGeneratorFromEncodedFactory(ImageGeneratorFromEncodedFactory);
 };
 
 class SkAutoGraphics {