Add --matrix to DM, to play around with and maybe use on a bot.

dm/DMCpuGMTask.cpp

 #include "DMCpuGMTask.h"
 #include "DMPipeTask.h"
 #include "DMQuiltTask.h"
 #include "DMSerializeTask.h"
 #include "DMUtil.h"
 #include "DMWriteTask.h"
 
 namespace DM {
 
 CpuGMTask::CpuGMTask(const char* config,
                      Reporter* reporter,
                      TaskRunner* taskRunner,
                      skiagm::GMRegistry::Factory gmFactory,
                      SkColorType colorType)
     : CpuTask(reporter, taskRunner)
     , fGMFactory(gmFactory)
     , fGM(fGMFactory(NULL))
     , fName(UnderJoin(fGM->getName(), config))
     , fColorType(colorType)
     {}
 
 void CpuGMTask::draw() {
     SkBitmap bm;
     AllocatePixels(fColorType, fGM->getISize().width(), fGM->getISize().height(), &bm);
 
     SkCanvas canvas(bm);
+    CanvasPreflight(&canvas);
     canvas.concat(fGM->getInitialTransform());
     fGM->draw(&canvas);
     canvas.flush();
 
 #define SPAWN(ChildTask, ...) this->spawnChild(SkNEW_ARGS(ChildTask, (*this, __VA_ARGS__)))
     SPAWN(PipeTask, fGMFactory(NULL), bm, PipeTask::kInProcess_Mode);
     SPAWN(PipeTask, fGMFactory(NULL), bm, PipeTask::kCrossProcess_Mode);
     SPAWN(PipeTask, fGMFactory(NULL), bm, PipeTask::kSharedAddress_Mode);
 
     SPAWN(QuiltTask, fGMFactory(NULL), bm, QuiltTask::kNone_BBH,     QuiltTask::kDefault_Backend);
@@ skipping 14 matching lines @@
     if (kRGB_565_SkColorType == fColorType && (fGM->getFlags() & skiagm::GM::kSkip565_Flag)) {
         return true;
     }
     if (fGM->getFlags() & skiagm::GM::kGPUOnly_Flag) {
         return true;
     }
     return false;
 }
 
 }  // namespace DM