Add implementation of path ops

src/pathops/SkPathOpsCommon.h

Index: src/pathops/SkPathOpsCommon.h
===================================================================
--- src/pathops/SkPathOpsCommon.h	(revision 0)
+++ src/pathops/SkPathOpsCommon.h	(revision 0)
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkPathOpsCommon_DEFINED
+#define SkPathOpsCommon_DEFINED
+
+#include "SkOpContour.h"
+
+class SkPathWriter;
+
+void Assemble(const SkPathWriter& path, SkPathWriter& simple);
+SkOpSegment* FindChase(SkTDArray<SkOpSpan*>& chase, int& tIndex, int& endIndex);
+SkOpSegment* FindSortableTop(SkTDArray<SkOpContour*>& contourList, bool& firstContour, int& index,
+                             int& endIndex, SkPoint& topLeft, bool& unsortable, bool& done,
+                             bool binary);
+SkOpSegment* FindUndone(SkTDArray<SkOpContour*>& contourList, int& start, int& end);
+void FixOtherTIndex(SkTDArray<SkOpContour*>& contourList);
+void MakeContourList(SkTArray<SkOpContour>& contours, SkTDArray<SkOpContour*>& list,
+                     bool evenOdd, bool oppEvenOdd);
+void SortSegments(SkTDArray<SkOpContour*>& contourList);
+
+#if DEBUG_ACTIVE_SPANS
+void DebugShowActiveSpans(SkTDArray<SkOpContour*>& contourList);
+#endif
+
+#endif