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diff --git a/gfx/skia/skia/src/utils/SkPolyUtils.h b/gfx/skia/skia/src/utils/SkPolyUtils.h
new file mode 100644
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+++ b/gfx/skia/skia/src/utils/SkPolyUtils.h
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+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkOffsetPolygon_DEFINED
+#define SkOffsetPolygon_DEFINED
+
+#include "include/core/SkPoint.h"
+#include "include/core/SkScalar.h"
+
+#include <cstdint>
+
+#if !defined(SK_ENABLE_OPTIMIZE_SIZE)
+struct SkRect;
+template <typename T> class SkTDArray;
+
+/**
+ * Generates a polygon that is inset a constant from the boundary of a given convex polygon.
+ * The input polygon is expected to have values clamped to the nearest 1/16th.
+ *
+ * @param inputPolygonVerts  Array of points representing the vertices of the original polygon.
+ *  It should be convex and have no coincident points.
+ * @param inputPolygonSize  Number of vertices in the original polygon.
+ * @param inset  How far we wish to inset the polygon. This should be a positive value.
+ * @param insetPolygon  The resulting inset polygon, if any.
+ * @return true if an inset polygon exists, false otherwise.
+ */
+bool SkInsetConvexPolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize,
+                          SkScalar inset, SkTDArray<SkPoint>* insetPolygon);
+
+/**
+ * Generates a simple polygon (if possible) that is offset a constant distance from the boundary
+ * of a given simple polygon.
+ * The input polygon must be simple, have no coincident vertices or collinear edges, and have
+ * values clamped to the nearest 1/16th.
+ *
+ * @param inputPolygonVerts  Array of points representing the vertices of the original polygon.
+ * @param inputPolygonSize  Number of vertices in the original polygon.
+ * @param bounds Bounding rectangle for the original polygon.
+ * @param offset How far we wish to offset the polygon.
+ *   Positive values indicate insetting, negative values outsetting.
+ * @param offsetPolgon  The resulting offset polygon, if any.
+ * @param polygonIndices  The indices of the original polygon that map to the new one.
+ * @return true if an offset simple polygon exists, false otherwise.
+ */
+bool SkOffsetSimplePolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize,
+                           const SkRect& bounds, SkScalar offset, SkTDArray<SkPoint>* offsetPolygon,
+                           SkTDArray<int>* polygonIndices = nullptr);
+
+/**
+ * Compute the number of points needed for a circular join when offsetting a vertex.
+ * The lengths of offset0 and offset1 don't have to equal |offset| -- only the direction matters.
+ * The segment lengths will be approximately four pixels.
+ *
+ * @param offset0  Starting offset vector direction.
+ * @param offset1  Ending offset vector direction.
+ * @param offset  Offset value (can be negative).
+ * @param rotSin  Sine of rotation delta per step.
+ * @param rotCos  Cosine of rotation delta per step.
+ * @param n  Number of steps to fill out the arc.
+ * @return true for success, false otherwise
+ */
+bool SkComputeRadialSteps(const SkVector& offset0, const SkVector& offset1, SkScalar offset,
+                          SkScalar* rotSin, SkScalar* rotCos, int* n);
+
+/**
+ * Determine winding direction for a polygon.
+ * The input polygon must be simple or the result will be meaningless.
+ *
+ * @param polygonVerts  Array of points representing the vertices of the polygon.
+ * @param polygonSize  Number of vertices in the polygon.
+ * @return 1 for cw, -1 for ccw, and 0 if zero signed area (either degenerate or self-intersecting).
+ *         The y-axis is assumed to be pointing down.
+ */
+int SkGetPolygonWinding(const SkPoint* polygonVerts, int polygonSize);
+
+/**
+ * Determine whether a polygon is convex or not.
+ *
+ * @param polygonVerts  Array of points representing the vertices of the polygon.
+ * @param polygonSize  Number of vertices in the polygon.
+ * @return true if the polygon is convex, false otherwise.
+ */
+bool SkIsConvexPolygon(const SkPoint* polygonVerts, int polygonSize);
+
+/**
+ * Determine whether a polygon is simple (i.e., not self-intersecting) or not.
+ * The input polygon must have no coincident vertices or the test will fail.
+ * The polygon is also expected to have values clamped to the nearest 1/16th.
+ *
+ * @param polygonVerts  Array of points representing the vertices of the polygon.
+ * @param polygonSize  Number of vertices in the polygon.
+ * @return true if the polygon is simple, false otherwise.
+ */
+ bool SkIsSimplePolygon(const SkPoint* polygonVerts, int polygonSize);
+
+ /**
+  * Compute indices to triangulate the given polygon.
+  * The input polygon must be simple (i.e. it is not self-intersecting)
+  * and have no coincident vertices or collinear edges.
+  *
+  * @param polygonVerts  Array of points representing the vertices of the polygon.
+  * @param indexMap Mapping from index in the given array to the final index in the triangulation.
+  * @param polygonSize  Number of vertices in the polygon.
+  * @param triangleIndices  Indices of the resulting triangulation.
+  * @return true if successful, false otherwise.
+  */
+ bool SkTriangulateSimplePolygon(const SkPoint* polygonVerts, uint16_t* indexMap, int polygonSize,
+                                 SkTDArray<uint16_t>* triangleIndices);
+
+#endif // !defined(SK_ENABLE_OPTIMIZE_SIZE)
+
+#endif