move SkPathRef.h into private

Bug: skia:
Change-Id: I3370c594301ae833ec1fe3cb16ac544e5b2128e8
Reviewed-on: https://skia-review.googlesource.com/18982
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

gn/core.gni

@@ -421,7 +421,6 @@ skia_core_sources = [
   "$_include/core/SkPath.h",
   "$_include/core/SkPathEffect.h",
   "$_include/core/SkPathMeasure.h",
-  "$_include/core/SkPathRef.h",
   "$_include/core/SkPicture.h",
   "$_include/core/SkPictureAnalyzer.h",
   "$_include/core/SkPictureRecorder.h",
@@ -460,6 +459,7 @@ skia_core_sources = [
   "$_include/private/SkMessageBus.h",
   "$_include/private/SkMutex.h",
   "$_include/private/SkOnce.h",
+  "$_include/private/SkPathRef.h",
   "$_include/private/SkSemaphore.h",
   "$_include/private/SkShadowFlags.h",
   "$_include/private/SkSpinlock.h",

include/core/SkPath.h

@@ -9,7 +9,7 @@
 #define SkPath_DEFINED
 
 #include "SkMatrix.h"
-#include "SkPathRef.h"
+#include "../private/SkPathRef.h"
 
 class SkAutoPathBoundsUpdate;
 class SkRRect;

tests/RRectInPathTest.cpp

@@ -7,7 +7,7 @@
 
 #include "SkMatrix.h"
 #include "SkPath.h"
-#include "SkPathRef.h"
+//#include "SkPathRef.h"
 #include "SkRRect.h"
 #include "Test.h"