Image filters: implement offsets in GPU path.

src/effects/SkBicubicImageFilter.cpp

Index: src/effects/SkBicubicImageFilter.cpp
diff --git a/src/effects/SkBicubicImageFilter.cpp b/src/effects/SkBicubicImageFilter.cpp
index 2d0a17a116d5f15d09e576faf8cb0046c306fcc6..a97a768de94de03cd600c81d97145e3ae5b9bfe9 100644
--- a/src/effects/SkBicubicImageFilter.cpp
+++ b/src/effects/SkBicubicImageFilter.cpp
@@ -341,9 +341,9 @@ GrEffectRef* GrBicubicEffect::TestCreate(SkMWCRandom* random,
     return GrBicubicEffect::Create(textures[texIdx], coefficients);
 }
 
-bool SkBicubicImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result) {
+bool SkBicubicImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result, SkIPoint* offset) {
     SkBitmap srcBM;
-    if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, &srcBM)) {
+    if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, &srcBM, offset)) {
         return false;
     }
     GrTexture* srcTexture = srcBM.getTexture();