Fix SKPBench tiling so MPD and non-MPD match

bench/SKPBench.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 "SKPBench.h"
 #include "SkCommandLineFlags.h"
 #include "SkMultiPictureDraw.h"
@@ skipping 39 matching lines @@
     int xTiles = SkScalarCeilToInt(bounds.width()  / SkIntToScalar(FLAGS_benchTile));
     int yTiles = SkScalarCeilToInt(bounds.height() / SkIntToScalar(FLAGS_benchTile));
 
     fSurfaces.setReserve(xTiles * yTiles);
     fTileRects.setReserve(xTiles * yTiles);
 
     SkImageInfo ii = canvas->imageInfo().makeWH(FLAGS_benchTile, FLAGS_benchTile);
 
     for (int y = bounds.fTop; y < bounds.fBottom; y += FLAGS_benchTile) {
         for (int x = bounds.fLeft; x < bounds.fRight; x += FLAGS_benchTile) {
-            *fTileRects.append() = SkIRect::MakeXYWH(x, y, FLAGS_benchTile, FLAGS_benchTile);
+            const SkIRect tileRect = SkIRect::MakeXYWH(x, y, FLAGS_benchTile, FLAGS_benchTile);
+            *fTileRects.append() = tileRect;
             *fSurfaces.push() = canvas->newSurface(ii);
+
+            // Never want the contents of a tile to include stuff the parent
+            // canvas clips out
+            SkRect clip = SkRect::Make(bounds);
+            clip.offset(-SkIntToScalar(tileRect.fLeft), -SkIntToScalar(tileRect.fTop));
+            fSurfaces.top()->getCanvas()->clipRect(clip);
+
             fSurfaces.top()->getCanvas()->setMatrix(canvas->getTotalMatrix());
             fSurfaces.top()->getCanvas()->scale(fScale, fScale);
         }
     }
 }
 
 void SKPBench::onPerCanvasPostDraw(SkCanvas* canvas) {
     if (!fUseMultiPictureDraw) {
         return;
     }
@@ skipping 41 matching lines @@
         SkIRect bounds;
         SkAssertResult(canvas->getClipDeviceBounds(&bounds));
 
         SkAutoCanvasRestore overall(canvas, true/*save now*/);
         canvas->scale(fScale, fScale);
 
         for (int i = 0; i < loops; i++) {
             for (int y = bounds.fTop; y < bounds.fBottom; y += FLAGS_benchTile) {
                 for (int x = bounds.fLeft; x < bounds.fRight; x += FLAGS_benchTile) {
                     SkAutoCanvasRestore perTile(canvas, true/*save now*/);
-                    canvas->clipRect(SkRect::Make(
-                                SkIRect::MakeXYWH(x, y, FLAGS_benchTile, FLAGS_benchTile)));
+                    canvas->clipRect(SkRect::MakeXYWH(x/fScale, y/fScale,
+                                                      FLAGS_benchTile/fScale,
+                                                      FLAGS_benchTile/fScale));
                     fPic->playback(canvas);
                 }
             }
 
             canvas->flush();
         }
     }
 }