Revert of Revert of Fix SkTextBlob offset semantics.

src/pdf/SkPDFDeviceFlattener.h

Index: src/pdf/SkPDFDeviceFlattener.h
diff --git a/src/pdf/SkPDFDeviceFlattener.h b/src/pdf/SkPDFDeviceFlattener.h
index f1047db3fc19ecd23652baa4394206331de5852f..bb152379962938dcf04ab1c0b7e82bbb7d2f00a6 100644
--- a/src/pdf/SkPDFDeviceFlattener.h
+++ b/src/pdf/SkPDFDeviceFlattener.h
@@ -37,8 +37,8 @@
     virtual void drawText(const SkDraw&, const void* text, size_t len,
                           SkScalar x, SkScalar y, const SkPaint&) SK_OVERRIDE;
     virtual void drawPosText(const SkDraw&, const void* text, size_t len,
-                             const SkScalar pos[], SkScalar constY,
-                             int scalarsPerPos, const SkPaint&) SK_OVERRIDE;
+                             const SkScalar pos[], int scalarsPerPos,
+                             const SkPoint& offset, const SkPaint&) SK_OVERRIDE;
     virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
                                 const SkPath& path, const SkMatrix* matrix,
                                 const SkPaint& paint) SK_OVERRIDE;