Add dest type hint to SkShader::ContextRec

src/core/SkBlitter.h

 /*
  * Copyright 2006 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 SkBlitter_DEFINED
 #define SkBlitter_DEFINED
 
@@ skipping 119 matching lines @@
                              SkTBlitterAllocator*,
                              bool drawCoverage = false);
 
     static SkBlitter* ChooseSprite(const SkPixmap& dst,
                                    const SkPaint&,
                                    const SkPixmap& src,
                                    int left, int top,
                                    SkTBlitterAllocator*);
     ///@}
 
+    static SkShader::ContextRec::DstType PreferredShaderDest(const SkImageInfo&);
+
 protected:
     SkAutoMalloc fBlitMemory;
 };
 
 /** This blitter silently never draws anything.
 */
 class SkNullBlitter : public SkBlitter {
 public:
     void blitH(int x, int y, int width) override;
     void blitAntiH(int x, int y, const SkAlpha[], const int16_t runs[]) override;
@@ skipping 81 matching lines @@
     SkBlitter*  apply(SkBlitter* blitter, const SkRegion* clip,
                       const SkIRect* bounds = nullptr);
 
 private:
     SkNullBlitter       fNullBlitter;
     SkRectClipBlitter   fRectBlitter;
     SkRgnClipBlitter    fRgnBlitter;
 };
 
 #endif