Create GrDraw and start fast pathing src over rects

src/gpu/draws/GrDraw.cpp

Index: src/gpu/draws/GrDraw.cpp
diff --git a/tools/VisualBench/VisualFlags.cpp b/src/gpu/draws/GrDraw.cpp
similarity index 54%
copy from tools/VisualBench/VisualFlags.cpp
copy to src/gpu/draws/GrDraw.cpp
index 80435ca3996629970843cb980dd84133e33b36d9..e6208028f12989d8f2de0814ac0804a88ff9b135 100644
--- a/tools/VisualBench/VisualFlags.cpp
+++ b/src/gpu/draws/GrDraw.cpp
@@ -5,6 +5,7 @@
  * found in the LICENSE file.
  */
 
-#include "VisualFlags.h"
+#include "GrDraw.h"
 
-DEFINE_int32(msaa, 0, "Number of msaa samples.");
+// Initial static variable from GrDraw
+int32_t GrDraw::gCurrDrawClassID = GrDraw::kIllegalDrawClassID;