Expose drawTextBlob to devices.

include/core/SkDevice.h

 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDevice_DEFINED
 #define SkDevice_DEFINED
 
@@ skipping 224 matching lines @@
                              const SkScalar pos[], SkScalar constY,
                              int scalarsPerPos, const SkPaint& paint) = 0;
     virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
                                 const SkPath& path, const SkMatrix* matrix,
                                 const SkPaint& paint) = 0;
     virtual void drawVertices(const SkDraw&, SkCanvas::VertexMode, int vertexCount,
                               const SkPoint verts[], const SkPoint texs[],
                               const SkColor colors[], SkXfermode* xmode,
                               const uint16_t indices[], int indexCount,
                               const SkPaint& paint) = 0;
+    // default implementation unrolls the blob runs.
+    virtual void drawTextBlob(const SkDraw&, const SkTextBlob*, SkScalar x, SkScalar y,
+                              const SkPaint& paint);
     // default implementation calls drawVertices
     virtual void drawPatch(const SkDraw&, const SkPoint cubics[12], const SkColor colors[4],
                            const SkPoint texCoords[4], SkXfermode* xmode, const SkPaint& paint);
     /** The SkDevice passed will be an SkDevice which was returned by a call to
         onCreateDevice on this device with kSaveLayer_Usage.
      */
     virtual void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                             const SkPaint&) = 0;
 
     bool readPixels(const SkImageInfo&, void* dst, size_t rowBytes, int x, int y);
@@ skipping 133 matching lines @@
     SkMetaData* fMetaData;
 
 #ifdef SK_DEBUG
     bool        fAttachedToCanvas;
 #endif
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif