Fold gmtoskp into DM, as --src gm --config skp.

dm/DM.cpp

 #include "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
 #include "OverwriteLine.h"
 #include "ProcStats.h"
 #include "SkBBHFactory.h"
 #include "SkChecksum.h"
 #include "SkCommonFlags.h"
 #include "SkForceLinking.h"
 #include "SkGraphics.h"
@@ skipping 190 matching lines @@
     #endif
     #if SK_MESA
         SINK("mesa",       GPUSink, Gr::kMESA_GLContextType,   api,  0, false, FLAGS_gpu_threading);
     #endif
     }
 
     if (FLAGS_cpu) {
         SINK("565",  RasterSink, kRGB_565_SkColorType);
         SINK("8888", RasterSink, kN32_SkColorType);
         SINK("pdf",  PDFSink);
+        SINK("skp",  SKPSink);
     }
 #undef SINK
     return NULL;
 }
 
 static Sink* create_via(const char* tag, Sink* wrapped) {
 #define VIA(t, via, ...) if (0 == strcmp(t, tag)) { return new via(__VA_ARGS__); }
     VIA("pipe",      ViaPipe,          wrapped);
     VIA("serialize", ViaSerialization, wrapped);
     VIA("tiles",     ViaTiles, 256, 256,               NULL, wrapped);
@@ skipping 308 matching lines @@
     }
     return 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