Reduce overdraw in MultiPictureDraw Sierpinski GM

gm/multipicturedraw.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 
 #include "SkColorFilter.h"
@@ skipping 137 matching lines @@
     fill.setColor(SK_ColorLTGRAY);;
 
     SkPaint stroke;
     stroke.setStyle(SkPaint::kStroke_Style);
     stroke.setStrokeWidth(3);
 
     SkPictureRecorder recorder;
 
     SkCanvas* canvas = recorder.beginRecording(SkIntToScalar(kPicWidth),
                                                SkIntToScalar(kPicHeight));
+    SkRect r = tri.getBounds();
+    r.outset(2.0f, 2.0f);       // outset for stroke
+    canvas->clipRect(r);
     // The saveLayer/restore block is to exercise layer hoisting
     canvas->saveLayer(NULL, NULL);
         canvas->drawPath(tri, fill);
         canvas->drawPath(tri, stroke);
     canvas->restore();
 
     return recorder.endRecording();
 }
 
 static const SkPicture* make_sub_picture(const SkPicture* tri) {
@@ skipping 371 matching lines @@
                                                 MultiPictureDraw::kTiled_Layout));)
     DEF_GM(return SkNEW_ARGS(MultiPictureDraw, (MultiPictureDraw::kPathClipMulti_Content,
                                                 MultiPictureDraw::kTiled_Layout));)
     DEF_GM(return SkNEW_ARGS(MultiPictureDraw, (MultiPictureDraw::kInvPathClipMulti_Content,
                                                 MultiPictureDraw::kTiled_Layout));)
     DEF_GM(return SkNEW_ARGS(MultiPictureDraw, (MultiPictureDraw::kSierpinski_Content,
                                                 MultiPictureDraw::kTiled_Layout));)
     DEF_GM(return SkNEW_ARGS(MultiPictureDraw, (MultiPictureDraw::kBigLayer_Content,
                                                 MultiPictureDraw::kTiled_Layout));)
 }