GMs: change some GMs to use SkImage over SkBitmap

tools/Resources.h

Index: tools/Resources.h
diff --git a/tools/Resources.h b/tools/Resources.h
index c9785a574c6e443d99312de8bc707718401aa4c3..5e76eb3ae81693449b73f564af5db55651787c8a 100644
--- a/tools/Resources.h
+++ b/tools/Resources.h
@@ -11,6 +11,7 @@
 #include "SkString.h"
 
 class SkBitmap;
+class SkImage;
 class SkStreamAsset;
 class SkTypeface;
 
@@ -18,6 +19,7 @@ SkString GetResourcePath(const char* resource = "");
 void SetResourcePath(const char* );
 
 bool GetResourceAsBitmap(const char* resource, SkBitmap* dst);
+SkImage* GetResourceAsImage(const char* resource);
 SkStreamAsset* GetResourceAsStream(const char* resource);
 SkTypeface* GetResourceAsTypeface(const char* resource);