Flush GrContext between benchmark draw loops

tools/VisualBench/VisualBenchmarkStream.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  */
 
 #include <VisualBench/VisualBenchmarkStream.h>
 #include <VisualBench/WrappedBenchmark.h>
 #include "GMBench.h"
 #include "SkOSFile.h"
 #include "SkPath.h"
 #include "SkPictureRecorder.h"
 #include "SkStream.h"
 #include "sk_tool_utils.h"
 #include "VisualFlags.h"
 #include "VisualSKPBench.h"
 
+#if SK_SUPPORT_GPU
+#include "GrContext.h"
+#endif
+
 DEFINE_bool(cpu, false, "Run in CPU mode?");
 DEFINE_string2(match, m, nullptr,
                "[~][^]substring[$] [...] of bench name to run.\n"
                "Multiple matches may be separated by spaces.\n"
                "~ causes a matching bench to always be skipped\n"
                "^ requires the start of the bench to match\n"
                "$ requires the end of the bench to match\n"
                "^ and $ requires an exact match\n"
                "If a bench does not match any list entry,\n"
                "it is skipped unless some list entry starts with ~");
@@ skipping 15 matching lines @@
         paint.setStyle(SkPaint::kStroke_Style);
         paint.setStrokeWidth(2);
 
         SkPaint perlinPaint;
         perlinPaint.setShader(SkPerlinNoiseShader::CreateTurbulence(0.1f, 0.1f, 1, 0,
                                                                     nullptr))->unref();
         SkRect rect = SkRect::MakeLTRB(0., 0., 400., 400.);
         for (int i = 0; i < loops; i++) {
             canvas->drawPath(fPath, paint);
             canvas->drawRect(rect, perlinPaint);
+#if SK_SUPPORT_GPU
+            // Ensure the GrContext doesn't batch across draw loops.
+            if (GrContext* context = canvas->getGrContext()) {
+                context->flush();
+            }
+#endif
         }
     }
     SkPath fPath;
 };
 
 VisualBenchmarkStream::VisualBenchmarkStream()
     : fBenches(BenchRegistry::Head())
     , fGMs(skiagm::GMRegistry::Head())
     , fSourceType(nullptr)
     , fBenchType(nullptr)
@@ skipping 94 matching lines @@
         }
 
         SkString name = SkOSPath::Basename(path.c_str());
         fSourceType = "skp";
         fBenchType = "playback";
         return new VisualSKPBench(name.c_str(), pic.get());
     }
 
     return nullptr;
 }