Revert of Revert of Fix SkTextBlob offset semantics.

src/utils/SkDeferredCanvas.cpp

Index: src/utils/SkDeferredCanvas.cpp
diff --git a/src/utils/SkDeferredCanvas.cpp b/src/utils/SkDeferredCanvas.cpp
index c8402dda4a4e666b3d3ed9f0fedcc32ac7d91bdc..06f7bb089ab07ebebfd9ad7a99c9f8af0a5e11d9 100644
--- a/src/utils/SkDeferredCanvas.cpp
+++ b/src/utils/SkDeferredCanvas.cpp
@@ -210,8 +210,8 @@
                             SkScalar x, SkScalar y, const SkPaint& paint) SK_OVERRIDE
         {SkASSERT(0);}
     virtual void drawPosText(const SkDraw&, const void* text, size_t len,
-                                const SkScalar pos[], SkScalar constY,
-                                int scalarsPerPos, const SkPaint& paint) SK_OVERRIDE
+                             const SkScalar pos[], int scalarsPerPos,
+                             const SkPoint& offset, const SkPaint& paint) SK_OVERRIDE
         {SkASSERT(0);}
     virtual void drawTextOnPath(const SkDraw&, const void* text,
                                 size_t len, const SkPath& path,