diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/core/SkLineClipper.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/include/core/SkLineClipper.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,47 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkLineClipper_DEFINED
+#define SkLineClipper_DEFINED
+
+#include "SkRect.h"
+#include "SkPoint.h"
+
+class SkLineClipper {
+public:
+    enum {
+        kMaxPoints = 4,
+        kMaxClippedLineSegments = kMaxPoints - 1
+    };
+
+    /*  Clip the line pts[0]...pts[1] against clip, ignoring segments that
+        lie completely above or below the clip. For portions to the left or
+        right, turn those into vertical line segments that are aligned to the
+        edge of the clip.
+
+        Return the number of line segments that result, and store the end-points
+        of those segments sequentially in lines as follows:
+            1st segment: lines[0]..lines[1]
+            2nd segment: lines[1]..lines[2]
+            3rd segment: lines[2]..lines[3]
+     */
+    static int ClipLine(const SkPoint pts[2], const SkRect& clip,
+                        SkPoint lines[kMaxPoints]);
+
+    /*  Intersect the line segment against the rect. If there is a non-empty
+        resulting segment, return true and set dst[] to that segment. If not,
+        return false and ignore dst[].
+
+        ClipLine is specialized for scan-conversion, as it adds vertical
+        segments on the sides to show where the line extended beyond the
+        left or right sides. IntersectLine does not.
+     */
+    static bool IntersectLine(const SkPoint src[2], const SkRect& clip,
+                              SkPoint dst[2]);
+};
+
+#endif