Fix rendering artifacts in pull-saveLayers-forward mode

src/gpu/GrPictureUtils.h

Index: src/gpu/GrPictureUtils.h
===================================================================
--- src/gpu/GrPictureUtils.h	(revision 14658)
+++ src/gpu/GrPictureUtils.h	(working copy)
@@ -27,8 +27,8 @@
         // the translation needed to map the layer's top-left point to the origin.
         SkMatrix fCTM;
         // The offset that needs to be passed to drawBitmap to correctly
-        // position the pre-rendered layer.
-        SkPoint fOffset;
+        // position the pre-rendered layer. It is in device space.
+        SkIPoint fOffset;
         // The paint to use on restore. NULL if the paint was not copyable (and
         // thus that this layer should not be pulled forward).
         const SkPaint* fPaint;