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/samplecode/SampleComplexClip.cpp b/samplecode/SampleComplexClip.cpp
index ae8a20f..b9c9307 100644
--- a/samplecode/SampleComplexClip.cpp
+++ b/samplecode/SampleComplexClip.cpp
@@ -4,10 +4,12 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
 #include "SampleCode.h"
 #include "SkCanvas.h"
 #include "SkPath.h"
 #include "SkView.h"
+#include "SkClipOpPriv.h"
 
 class ComplexClipView : public SampleView {
 public: