Check all scratch texture allocations for image filters.

src/core/SkImageFilter.cpp

Index: src/core/SkImageFilter.cpp
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index cf1f07696b92270b5a6225791f4715bc147b619f..4a9a22e63445bde4b0c6705403fe0dc08ee31805 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -256,6 +256,9 @@ bool SkImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const Cont
     desc.fConfig = kRGBA_8888_GrPixelConfig;
 
     GrAutoScratchTexture dst(context, desc);
+    if (NULL == dst.texture()) {
+        return false;
+    }
     GrContext::AutoMatrix am;
     am.setIdentity(context);
     GrContext::AutoRenderTarget art(context, dst.texture()->asRenderTarget());