Adding premul and 565 swizzles for bmp:

src/codec/SkMaskSwizzler.h

Index: src/codec/SkMaskSwizzler.h
diff --git a/src/codec/SkMaskSwizzler.h b/src/codec/SkMaskSwizzler.h
index 9351f0228ba2a771e418a768752ed71b1bbf750b..69103023c63e06c7df65427a685382b146d48a04 100644
--- a/src/codec/SkMaskSwizzler.h
+++ b/src/codec/SkMaskSwizzler.h
@@ -25,15 +25,16 @@ public:
      *
      */
     static SkMaskSwizzler* CreateMaskSwizzler(const SkImageInfo& imageInfo,
+                                              void* dst, size_t dstRowBytes,
                                               SkMasks* masks,
                                               uint32_t bitsPerPixel);
 
     /*
      *
-     * Swizzle the next row
+     * Swizzle the row with the specified y value
      *
      */
-    SkSwizzler::ResultAlpha next(void* dst, const uint8_t* src);
+    SkSwizzler::ResultAlpha next(const uint8_t* SK_RESTRICT src, int y);
 
 private:
 
@@ -51,10 +52,13 @@ private:
      * Constructor for mask swizzler
      *
      */
-    SkMaskSwizzler(const SkImageInfo& info, SkMasks* masks, RowProc proc);
+    SkMaskSwizzler(const SkImageInfo& info, void* dst, size_t dstRowBytes,
+            SkMasks* masks, RowProc proc);
 
     // Fields
-    const SkImageInfo& fImageInfo;
-    SkMasks*           fMasks;     // unowned
+    const SkImageInfo& fDstInfo;
+    void*              fDst;
+    size_t             fDstRowBytes;
+    SkMasks*           fMasks;       // unowned
     const RowProc      fRowProc;
 };