Option for SkCodec to treat dst as all zeroes.

src/codec/SkSwizzler.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkSwizzler_DEFINED
 #define SkSwizzler_DEFINED
 
-#include "SkTypes.h"
+#include "SkCodec.h"
 #include "SkColor.h"
 #include "SkImageInfo.h"
 
 class SkSwizzler : public SkNoncopyable {
 public:
     /**
      *  Enum describing the config of the source data.
      */
     enum SrcConfig {
         kGray,
@@ skipping 84 matching lines @@
      * Raises an error if each pixel is not stored in an even number of bytes
      *
      */
     static int BytesPerPixel(SrcConfig sc) {
         SkASSERT(SkIsAlign8(BitsPerPixel(sc)));
         return BitsPerPixel(sc) >> 3;
     }
 
     /**
      *  Create a new SkSwizzler.
-     *  @param sc SrcConfig
-     *  @param info dimensions() describe both the src and the dst.
+     *  @param SrcConfig Description of the format of the source.
+     *  @param SkImageInfo dimensions() describe both the src and the dst.
      *              Other fields describe the dst.
      *  @param dst Destination to write pixels. Must match info and dstRowBytes
      *  @param dstRowBytes rowBytes for dst.
-     *  @param skipZeroes Whether to skip writing zeroes. Useful if dst is
-     *              zero-initialized. The implementation may or may not respect this.
+     *  @param ZeroInitialized Whether dst is zero-initialized. The
+                               implementation may choose to skip writing zeroes
+     *                         if set to kYes_ZeroInitialized.
      *  @return A new SkSwizzler or NULL on failure.
      */
-    static SkSwizzler* CreateSwizzler(SrcConfig sc, const SkPMColor* ctable,
-                                      const SkImageInfo& info, void* dst,
-                                      size_t dstRowBytes, bool skipZeroes);
-
+    static SkSwizzler* CreateSwizzler(SrcConfig, const SkPMColor* ctable,
+                                      const SkImageInfo&, void* dst,
+                                      size_t dstRowBytes,
+                                      SkImageGenerator::ZeroInitialized);
     /**
      *  Swizzle the next line. Call height times, once for each row of source.
      *  @param src The next row of the source data.
      *  @return A result code describing if the row was fully opaque, fully
      *          transparent, or neither
      */
     ResultAlpha next(const uint8_t* SK_RESTRICT src);
 
     /**
      *
@@ skipping 45 matching lines @@
     const SkImageInfo   fDstInfo;
     void*               fDstRow;
     const size_t        fDstRowBytes;
     int                 fCurrY;
 
     SkSwizzler(RowProc proc, const SkPMColor* ctable, int deltaSrc,
                const SkImageInfo& info, void* dst, size_t rowBytes);
 
 };
 #endif // SkSwizzler_DEFINED