change SkClipOp to a class enum

BUG=skia:

Change-Id: I25dbe6d6b8666a2a0a7be7bdd2ae0b067868d14e
Reviewed-on: https://skia-review.googlesource.com/5718
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/tools/debugger/SkDrawCommand.cpp b/tools/debugger/SkDrawCommand.cpp
index 6cec6eb..4eaf2ea 100644
--- a/tools/debugger/SkDrawCommand.cpp
+++ b/tools/debugger/SkDrawCommand.cpp
@@ -26,6 +26,7 @@
 #include "SkValidatingReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "picture_utils.h"
+#include "SkClipOpPriv.h"
 
 #define SKDEBUGCANVAS_ATTRIBUTE_COMMAND           "command"
 #define SKDEBUGCANVAS_ATTRIBUTE_VISIBLE           "visible"