Use MacOS's CoreGraphics PDF Rasterizer in DM

dm/DM.cpp

 // Main binary for DM.
 // For a high-level overview, please see dm/README.
 
 #include "CrashHandler.h"
 #include "LazyDecodeBitmap.h"
 #include "SkCommonFlags.h"
 #include "SkForceLinking.h"
 #include "SkGraphics.h"
 #include "SkOSFile.h"
 #include "SkPicture.h"
@@ skipping 11 matching lines @@
 #include "DMReporter.h"
 #include "DMSKPTask.h"
 #include "DMTask.h"
 #include "DMTaskRunner.h"
 #include "DMTestTask.h"
 #include "DMWriteTask.h"
 
 #ifdef SK_BUILD_POPPLER
 #  include "SkPDFRasterizer.h"
 #  define RASTERIZE_PDF_PROC SkPopplerRasterizePDF
+#elif defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
+#  include "SkCGUtils.h"
+#  define RASTERIZE_PDF_PROC SkPDFDocumentToBitmap
 #else
 #  define RASTERIZE_PDF_PROC NULL
 #endif
 
 #include <ctype.h>
 
 using skiagm::GM;
 using skiagm::GMRegistry;
 using skiatest::Test;
 using skiatest::TestRegistry;
@@ skipping 198 matching lines @@
     report_failures(failures);
     return failures.count() > 0;
 }
 
 #if !defined(SK_BUILD_FOR_IOS) && !defined(SK_BUILD_FOR_NACL)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif