Change undefined SkGpuRenderTarget and SkGpuTexture forward declares to GrRenderTarget and GrTexture.

R=robertphillips@google.com, reed@google.com

Author: bsalomon@google.com

Review URL: https://chromiumcodereview.appspot.com/17269003

git-svn-id: http://skia.googlecode.com/svn/trunk@9775 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/SkGrPixelRef.h b/include/gpu/SkGrPixelRef.h
index ec1e22e..da4b8fa 100644
--- a/include/gpu/SkGrPixelRef.h
+++ b/include/gpu/SkGrPixelRef.h
@@ -51,7 +51,7 @@
     virtual ~SkGrPixelRef();
 
     // override from SkPixelRef
-    virtual SkGpuTexture* getTexture() SK_OVERRIDE;
+    virtual GrTexture* getTexture() SK_OVERRIDE;
 
     SK_DECLARE_UNFLATTENABLE_OBJECT()