Change undefined SkGpuRenderTarget and SkGpuTexture forward declares to GrRenderTarget and GrTextur…

src/effects/SkBlurImageFilter.cpp

 /*
  * Copyright 2011 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkBlurImageFilter.h"
 #include "SkColorPriv.h"
@@ skipping 180 matching lines @@
     }
     return true;
 }
 
 bool SkBlurImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result) {
 #if SK_SUPPORT_GPU
     SkBitmap input;
     if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, &input)) {
         return false;
     }
-    GrTexture* source = (GrTexture*) input.getTexture();
+    GrTexture* source = input.getTexture();
     SkRect rect;
     src.getBounds(&rect);
     SkAutoTUnref<GrTexture> tex(source->getContext()->gaussianBlur(source, false, rect,
         fSigma.width(), fSigma.height()));
     return SkImageFilterUtils::WrapTexture(tex, src.width(), src.height(), result);
 #else
     SkDEBUGFAIL("Should not call in GPU-less build");
     return false;
 #endif
 }