Revert of Revert of Turn on NVPR 4x MSAA by default when supported in DM and nanobench.

dm/DMGpuGMTask.cpp

 #include "DMGpuGMTask.h"
 #include "DMUtil.h"
 #include "DMWriteTask.h"
 #include "SkCommonFlags.h"
 #include "SkSurface.h"
 #include "SkTLS.h"
 
 namespace DM {
 
 GpuGMTask::GpuGMTask(const char* config,
                      Reporter* reporter,
                      TaskRunner* taskRunner,
                      skiagm::GMRegistry::Factory gmFactory,
                      GrContextFactory::GLContextType contextType,
                      GrGLStandard gpuAPI,
                      int sampleCount)
     : GpuTask(reporter, taskRunner)
     , fGM(gmFactory(NULL))
     , fName(UnderJoin(fGM->getName(), config))
     , fContextType(contextType)
     , fGpuAPI(gpuAPI)
     , fSampleCount(sampleCount)
     {}
 
+static bool gAlreadyWarned[GrContextFactory::kGLContextTypeCnt][kGrGLStandardCnt];
+
 void GpuGMTask::draw(GrContextFactory* grFactory) {
     SkImageInfo info = SkImageInfo::Make(SkScalarCeilToInt(fGM->width()),
                                          SkScalarCeilToInt(fGM->height()),
                                          kN32_SkColorType,
                                          kPremul_SkAlphaType);
     SkAutoTUnref<SkSurface> surface(NewGpuSurface(grFactory, fContextType, fGpuAPI, info,
                                                   fSampleCount));
     if (!surface) {
-        this->fail("Could not create context for the config and the api.");
+        if (!gAlreadyWarned[fContextType][fGpuAPI]) {
+            SkDebugf("FYI: couldn't create GPU context, type %d API %d.  Will skip.\n",
+                     fContextType, fGpuAPI);
+            gAlreadyWarned[fContextType][fGpuAPI] = true;
+        }
         return;
     }
     SkCanvas* canvas = surface->getCanvas();
     CanvasPreflight(canvas);
 
     canvas->concat(fGM->getInitialTransform());
     fGM->draw(canvas);
     canvas->flush();
 #if GR_CACHE_STATS && SK_SUPPORT_GPU
     if (FLAGS_veryVerbose) {
         grFactory->get(fContextType)->printCacheStats();
     }
 #endif
 
     SkBitmap bitmap;
     bitmap.setInfo(info);
     canvas->readPixels(&bitmap, 0, 0);
 
     this->spawnChild(SkNEW_ARGS(WriteTask, (*this, "GM", bitmap)));
 }
 
 bool GpuGMTask::shouldSkip() const {
     return kGPUDisabled || SkToBool(fGM->getFlags() & skiagm::GM::kSkipGPU_Flag);
 }
 
 }  // namespace DM