Fix SkTextBlob offset semantics.

src/core/SkBitmapDevice.cpp

Index: src/core/SkBitmapDevice.cpp
diff --git a/src/core/SkBitmapDevice.cpp b/src/core/SkBitmapDevice.cpp
index b48432efa0d348397a41ae73e3ce6ef73ae3f1e5..cc4155a29f44c6fd76129cf738ffa195efc0cb6b 100644
--- a/src/core/SkBitmapDevice.cpp
+++ b/src/core/SkBitmapDevice.cpp
@@ -329,9 +329,9 @@ void SkBitmapDevice::drawText(const SkDraw& draw, const void* text, size_t len,
 }
 
 void SkBitmapDevice::drawPosText(const SkDraw& draw, const void* text, size_t len,
-                                 const SkScalar xpos[], SkScalar y,
-                                 int scalarsPerPos, const SkPaint& paint) {
-    draw.drawPosText((const char*)text, len, xpos, y, scalarsPerPos, paint);
+                                 const SkScalar xpos[], int scalarsPerPos,
+                                 const SkPoint& offset, const SkPaint& paint) {
+    draw.drawPosText((const char*)text, len, xpos, scalarsPerPos, offset, paint);
 }
 
 void SkBitmapDevice::drawTextOnPath(const SkDraw& draw, const void* text,