Pass Rendertarget into context

src/effects/SkAlphaThresholdFilter.cpp

Index: src/effects/SkAlphaThresholdFilter.cpp
diff --git a/src/effects/SkAlphaThresholdFilter.cpp b/src/effects/SkAlphaThresholdFilter.cpp
index ab84a0cb726b236f19d751012d0d26ca973d0f58..a5b564f57bb51cf3029ac3341ce6932f85ed5d9c 100644
--- a/src/effects/SkAlphaThresholdFilter.cpp
+++ b/src/effects/SkAlphaThresholdFilter.cpp
@@ -285,7 +285,6 @@ bool SkAlphaThresholdFilterImpl::asFragmentProcessor(GrFragmentProcessor** fp,
         }
 
         {
-            GrContext::AutoRenderTarget art(context, maskTexture->asRenderTarget());
             GrPaint grPaint;
             grPaint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
             SkRegion::Iterator iter(fRegion);
@@ -293,7 +292,7 @@ bool SkAlphaThresholdFilterImpl::asFragmentProcessor(GrFragmentProcessor** fp,
 
             while (!iter.done()) {
                 SkRect rect = SkRect::Make(iter.rect());
-                context->drawRect(grPaint, in_matrix, rect);
+                context->drawRect(maskTexture->asRenderTarget(), grPaint, in_matrix, rect);
                 iter.next();
             }
         }