Switch GrEffect::onIsEqual signature back to GrEffect from GrEffectRef.

R=robertphillips@google.com
Review URL: https://codereview.appspot.com/7188046

git-svn-id: http://skia.googlecode.com/svn/trunk@7326 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 1880425..cdbfd7c 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -829,7 +829,7 @@
     }
 }
 
-bool GrGradientEffect::onIsEqual(const GrEffectRef& effect) const {
+bool GrGradientEffect::onIsEqual(const GrEffect& effect) const {
     const GrGradientEffect& s = CastEffect<GrGradientEffect>(effect);
     return fTextureAccess.getTexture() == s.fTextureAccess.getTexture()  &&
            fTextureAccess.getParams().getTileModeX() ==