Let DM work without a GPU.

dm/DMBenchTask.cpp

 #include "DMBenchTask.h"
 #include "DMUtil.h"
 #include "SkSurface.h"
 
 namespace DM {
 
 static SkString bench_name(const char* name, const char* config) {
     SkString result("bench ");
     result.appendf("%s_%s", name, config);
     return result;
@@ skipping 31 matching lines @@
 
 bool NonRenderingBenchTask::shouldSkip() const {
     return !fBench->isSuitableFor(SkBenchmark::kNonRendering_Backend);
 }
 
 bool CpuBenchTask::shouldSkip() const {
     return !fBench->isSuitableFor(SkBenchmark::kRaster_Backend);
 }
 
 bool GpuBenchTask::shouldSkip() const {
-    return !fBench->isSuitableFor(SkBenchmark::kGPU_Backend);
+    return kGPUDisabled || !fBench->isSuitableFor(SkBenchmark::kGPU_Backend);
 }
 
 static void draw_raster(SkBenchmark* bench, SkColorType colorType) {
     SkBitmap bitmap;
     SetupBitmap(colorType, bench, &bitmap);
     SkCanvas canvas(bitmap);
 
     bench->preDraw();
     bench->draw(1, &canvas);
     bench->postDraw();
 }
 
 void NonRenderingBenchTask::draw() {
     draw_raster(fBench.get(), kPMColor_SkColorType);
 }
 
 void CpuBenchTask::draw() {
     draw_raster(fBench.get(), fColorType);
 }
 
 void GpuBenchTask::draw(GrContextFactory* grFactory) {
     SkImageInfo info = SkImageInfo::Make(fBench->getSize().x(),
                                          fBench->getSize().y(),
                                          kPMColor_SkColorType,
                                          kPremul_SkAlphaType);
-    SkAutoTUnref<SkSurface> surface(SkSurface::NewRenderTarget(
-            grFactory->get(fContextType), info, fSampleCount));
+    SkAutoTUnref<SkSurface> surface(NewGpuSurface(grFactory, fContextType, info, fSampleCount));
 
     fBench->preDraw();
     fBench->draw(1, surface->getCanvas());
     fBench->postDraw();
 }
 
 }  // namespace DM