Flush GrContext between benchmark draw loops

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"
 #include "SkSurface.h"
 
+#if SK_SUPPORT_GPU
+#include "GrContext.h"
+#endif
+
 // These CPU tile sizes are not good per se, but they are similar to what Chrome uses.
 DEFINE_int32(CPUbenchTileW, 256, "Tile width  used for CPU SKP playback.");
 DEFINE_int32(CPUbenchTileH, 256, "Tile height used for CPU SKP playback.");
 
 DEFINE_int32(GPUbenchTileW, 1600, "Tile width  used for GPU SKP playback.");
 DEFINE_int32(GPUbenchTileH, 512, "Tile height used for GPU SKP playback.");
 
 SKPBench::SKPBench(const char* name, const SkPicture* pic, const SkIRect& clip, SkScalar scale,
                    bool useMultiPictureDraw, bool doLooping)
     : fPic(SkRef(pic))
@@ skipping 85 matching lines @@
     SkASSERT(fDoLooping || 1 == loops);
     if (fUseMultiPictureDraw) {
         for (int i = 0; i < loops; i++) {
             this->drawMPDPicture();
         }
     } else {
         for (int i = 0; i < loops; i++) {
             this->drawPicture();
         }
     }
+#if SK_SUPPORT_GPU
+    // Ensure the GrContext doesn't batch across draw loops.
+    if (GrContext* context = canvas->getGrContext()) {
+        context->flush();
+    }
+#endif
 }
 
 void SKPBench::drawMPDPicture() {
     SkMultiPictureDraw mpd;
 
     for (int j = 0; j < fTileRects.count(); ++j) {
         SkMatrix trans;
         trans.setTranslate(-fTileRects[j].fLeft/fScale,
                            -fTileRects[j].fTop/fScale);
         mpd.add(fSurfaces[j]->getCanvas(), fPic, &trans);
@@ skipping 10 matching lines @@
     for (int j = 0; j < fTileRects.count(); ++j) {
         const SkMatrix trans = SkMatrix::MakeTrans(-fTileRects[j].fLeft / fScale,
                                                    -fTileRects[j].fTop / fScale);
         fSurfaces[j]->getCanvas()->drawPicture(fPic, &trans, nullptr);
     }
 
     for (int j = 0; j < fTileRects.count(); ++j) {
         fSurfaces[j]->getCanvas()->flush();
     }
 }