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/src/gpu/SkGrPixelRef.cpp b/src/gpu/SkGrPixelRef.cpp
index 8751c5d..98819bf 100644
--- a/src/gpu/SkGrPixelRef.cpp
+++ b/src/gpu/SkGrPixelRef.cpp
@@ -128,9 +128,9 @@
     GrSafeUnref(fSurface);
 }
 
-SkGpuTexture* SkGrPixelRef::getTexture() {
+GrTexture* SkGrPixelRef::getTexture() {
     if (NULL != fSurface) {
-        return (SkGpuTexture*) fSurface->asTexture();
+        return fSurface->asTexture();
     }
     return NULL;
 }