Remove backend factories

BUG=skia:

Review URL: https://codereview.chromium.org/778453002
diff --git a/src/gpu/effects/GrOvalEffect.h b/src/gpu/effects/GrOvalEffect.h
index 41e22cc..8f85365 100644
--- a/src/gpu/effects/GrOvalEffect.h
+++ b/src/gpu/effects/GrOvalEffect.h
@@ -11,7 +11,7 @@
 #include "GrTypes.h"
 #include "GrTypesPriv.h"
 
-class GrProcessor;
+class GrFragmentProcessor;
 struct SkRect;
 
 namespace GrOvalEffect {