add flag to skip gpu test



git-svn-id: http://skia.googlecode.com/svn/trunk@8036 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/gm.h b/gm/gm.h
index 17541e4..646ef1a 100644
--- a/gm/gm.h
+++ b/gm/gm.h
@@ -40,6 +40,7 @@
             kSkipTiled_Flag         = 1 << 3,
             kSkip565_Flag           = 1 << 4,
             kSkipScaledReplay_Flag  = 1 << 5,
+            kSkipGPU_Flag           = 1 << 6,
         };
 
         void draw(SkCanvas*);