update dox for pathmeasure

Of note, the client need not keep the path around after creating/resetting the measure
object. The parts that are needed are copied, so the client is free to modify/delete
the path afterwards.

Bug: skia:
Change-Id: I9b9a0fd8e3cd6fd6c60de0017bcaee1fbc2fb893
Reviewed-on: https://skia-review.googlesource.com/c/190679
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Mike Reed <reed@google.com>
diff --git a/include/core/SkContourMeasure.h b/include/core/SkContourMeasure.h
index 223f3b5..f3ec519 100644
--- a/include/core/SkContourMeasure.h
+++ b/include/core/SkContourMeasure.h
@@ -92,9 +92,19 @@
 class SK_API SkContourMeasureIter : SkNoncopyable {
 public:
     SkContourMeasureIter();
+    /**
+     *  Initialize the Iter with a path.
+     *  The parts of the path that are needed are copied, so the client is free to modify/delete
+     *  the path after this call.
+     */
     SkContourMeasureIter(const SkPath& path, bool forceClosed, SkScalar resScale = 1);
     ~SkContourMeasureIter();
 
+    /**
+     *  Reset the Iter with a path.
+     *  The parts of the path that are needed are copied, so the client is free to modify/delete
+     *  the path after this call.
+     */
     void reset(const SkPath& path, bool forceClosed, SkScalar resScale = 1);
 
     /**
diff --git a/include/core/SkPathMeasure.h b/include/core/SkPathMeasure.h
index 9d77da2..c486d31 100644
--- a/include/core/SkPathMeasure.h
+++ b/include/core/SkPathMeasure.h
@@ -16,22 +16,18 @@
 class SK_API SkPathMeasure : SkNoncopyable {
 public:
     SkPathMeasure();
-    /** Initialize the pathmeasure with the specified path. The path must remain valid
-        for the lifetime of the measure object, or until setPath() is called with
-        a different path (or null), since the measure object keeps a pointer to the
-        path object (does not copy its data).
-
-        resScale controls the precision of the measure. values > 1 increase the
-        precision (and possible slow down the computation).
-    */
+    /** Initialize the pathmeasure with the specified path. The parts of the path that are needed
+     *  are copied, so the client is free to modify/delete the path after this call.
+     *
+     *  resScale controls the precision of the measure. values > 1 increase the
+     *  precision (and possible slow down the computation).
+     */
     SkPathMeasure(const SkPath& path, bool forceClosed, SkScalar resScale = 1);
     ~SkPathMeasure();
 
-    /** Reset the pathmeasure with the specified path. The path must remain valid
-        for the lifetime of the measure object, or until setPath() is called with
-        a different path (or null), since the measure object keeps a pointer to the
-        path object (does not copy its data).
-    */
+    /** Reset the pathmeasure with the specified path. The parts of the path that are needed
+     *  are copied, so the client is free to modify/delete the path after this call..
+     */
     void setPath(const SkPath*, bool forceClosed);
 
     /** Return the total length of the current contour, or 0 if no path