Optimize SkTileImageFilter destination bitmap size.

src/effects/SkTileImageFilter.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 "SkTileImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 17 matching lines @@
                                       const Context& ctx,
                                       SkBitmap* dst, SkIPoint* offset) const {
     SkBitmap source = src;
     SkIPoint srcOffset = SkIPoint::Make(0, 0);
     if (!this->filterInput(0, proxy, src, ctx, &source, &srcOffset)) {
         return false;
     }
 
     SkRect dstRect;
     ctx.ctm().mapRect(&dstRect, fDstRect);
+#ifndef SK_DISABLE_TILE_IMAGE_FILTER_DEST_OPTIMIZATION
+    if (!dstRect.intersect(SkRect::Make(ctx.clipBounds()))) {
+        offset->fX = offset->fY = 0;
+        return true;
+    }
+#endif
     const SkIRect dstIRect = dstRect.roundOut();
     int w = dstIRect.width();
     int h = dstIRect.height();
     if (!fSrcRect.width() || !fSrcRect.height() || !w || !h) {
         return false;
     }
 
     SkRect srcRect;
     ctx.ctm().mapRect(&srcRect, fSrcRect);
     SkIRect srcIRect;
@@ skipping 81 matching lines @@
     str->appendf(" dst: %.2f %.2f %.2f %.2f",
                  fDstRect.fLeft, fDstRect.fTop, fDstRect.fRight, fDstRect.fBottom);
     if (this->getInput(0)) {
         str->appendf("input: (");
         this->getInput(0)->toString(str);
         str->appendf(")");
     }
     str->append(")");
 }
 #endif