Update how SkPath handles fGenerationID and fSourcePath, and add tests to cover.

include/core/SkPath.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPath_DEFINED
@@ skipping 148 matching lines @@
      *
      * @return true if this path is an oval.
      *              Tracking whether a path is an oval is considered an
      *              optimization for performance and so some paths that are in
      *              fact ovals can report false.
      */
     bool isOval(SkRect* rect) const;
 
     /** Clear any lines and curves from the path, making it empty. This frees up
         internal storage associated with those segments.
+        On Android, does not change fSourcePath.
     */
     void reset();
 
     /** Similar to reset(), in that all lines and curves are removed from the
         path. However, any internal storage for those lines/curves is retained,
         making reuse of the path potentially faster.
+        On Android, does not change fSourcePath.
     */
     void rewind();
 
     /** Returns true if the path is empty (contains no lines or curves)
 
         @return true if the path is empty (contains no lines or curves)
     */
     bool isEmpty() const;
 
     /**
@@ skipping 814 matching lines @@
     bool isRectContour(bool allowPartial, int* currVerb, const SkPoint** pts,
                        bool* isClosed, Direction* direction) const;
 
     friend class SkAutoPathBoundsUpdate;
     friend class SkAutoDisableOvalCheck;
     friend class SkAutoDisableDirectionCheck;
     friend class SkBench_AddPathTest; // perf test pathTo/reversePathTo
 };
 
 #endif