Fix filter primitive bounds computations.

src/effects/SkComposeImageFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkComposeImageFilter.h"
 #include "SkReadBuffer.h"
@@ skipping 17 matching lines @@
                                          SkBitmap* result,
                                          SkIPoint* offset) const {
     SkBitmap tmp;
     SkIPoint innerOffset = SkIPoint::Make(0, 0);
     SkIPoint outerOffset = SkIPoint::Make(0, 0);
     if (!this->filterInput(1, proxy, src, ctx, &tmp, &innerOffset))
         return false;
 
     SkMatrix outerMatrix(ctx.ctm());
     outerMatrix.postTranslate(SkIntToScalar(-innerOffset.x()), SkIntToScalar(-innerOffset.y()));
-    Context outerContext(outerMatrix, ctx.clipBounds(), ctx.cache(), ctx.sizeConstraint());
+    SkIRect clipBounds = ctx.clipBounds();
+    clipBounds.offset(-innerOffset.x(), -innerOffset.y());
+    Context outerContext(outerMatrix, clipBounds, ctx.cache(), ctx.sizeConstraint());
     if (!this->filterInput(0, proxy, tmp, outerContext, result, &outerOffset, false)) {
         return false;
     }
 
     *offset = innerOffset + outerOffset;
     return true;
 }
 
 bool SkComposeImageFilter::onFilterBounds(const SkIRect& src,
                                           const SkMatrix& ctm,
@@ skipping 19 matching lines @@
 
     str->appendf("outer: ");
     outer->toString(str);
 
     str->appendf("inner: ");
     inner->toString(str);
 
     str->appendf(")");
 }
 #endif