Add GM option to allow the GPU context to be reset prior to each GM being run

gm/gmmain.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /*
  * Code for the "gm" (Golden Master) rendering comparison tool.
  *
@@ skipping 1386 matching lines @@
               "into this directory.");
 DEFINE_string(mismatchPath, "", "Write images for tests that failed due to "
               "pixel mismatches into this directory.");
 DEFINE_string(modulo, "", "[--modulo <remainder> <divisor>]: only run tests for which "
               "testIndex %% divisor == remainder.");
 DEFINE_bool(pdf, true, "Exercise the pdf rendering test pass.");
 DEFINE_bool(pipe, false, "Exercise the SkGPipe replay test pass.");
 DEFINE_string2(readPath, r, "", "Read reference images from this dir, and report "
                "any differences between those and the newly generated ones.");
 DEFINE_bool(replay, false, "Exercise the SkPicture replay test pass.");
+#if SK_SUPPORT_GPU
+DEFINE_bool(resetGpuContext, false, "Reset the GrContext prior to running each GM.");
+#endif
 DEFINE_string2(resourcePath, i, "", "Directory that stores image resources.");
 DEFINE_bool(rtree, false, "Exercise the R-Tree variant of SkPicture test pass.");
 DEFINE_bool(serialize, false, "Exercise the SkPicture serialization & deserialization test pass.");
 DEFINE_bool(simulatePipePlaybackFailure, false, "Simulate a rendering failure in pipe mode only.");
 DEFINE_bool(tiledPipe, false, "Exercise tiled SkGPipe replay.");
 DEFINE_bool(tileGrid, false, "Exercise the tile grid variant of SkPicture.");
 DEFINE_string(tileGridReplayScales, "", "Space separated list of floating-point scale "
               "factors to be used for tileGrid playback testing. Default value: 1.0");
 DEFINE_bool2(verbose, v, false, "Give more detail (e.g. list all GMs run, more info about "
              "each test).");
@@ skipping 121 matching lines @@
             continue;
         }
 
         // Now we know that we want to run this test and record its
         // success or failure.
         ErrorCombination errorsForThisConfig;
         GrSurface* gpuTarget = NULL;
 #if SK_SUPPORT_GPU
         SkAutoTUnref<GrSurface> auGpuTarget;
         if ((errorsForThisConfig.isEmpty()) && (kGPU_Backend == config.fBackend)) {
+            if (FLAGS_resetGpuContext) {
+                grFactory->destroyContexts();
+            }
             GrContext* gr = grFactory->get(config.fGLContextType);
             bool grSuccess = false;
             if (gr) {
                 // create a render target to back the device
                 GrTextureDesc desc;
                 desc.fConfig = kSkia8888_GrPixelConfig;
                 desc.fFlags = kRenderTarget_GrTextureFlagBit;
                 desc.fWidth = gm->getISize().width();
                 desc.fHeight = gm->getISize().height();
                 desc.fSampleCnt = config.fSampleCnt;
@@ skipping 713 matching lines @@
     if (FLAGS_forceBWtext) {
         canvas->setDrawFilter(SkNEW(BWTextDrawFilter))->unref();
     }
 }
 
 #if !defined(SK_BUILD_FOR_IOS) && !defined(SK_BUILD_FOR_NACL)
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif