Support decoding opaque to *premul

src/codec/SkMaskSwizzler.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
 #include "SkMaskSwizzler.h"
@@ skipping 232 matching lines @@
                             proc = &swizzle_mask16_to_n32_premul;
                             break;
                         case kOpaque_SkAlphaType:
                             proc = &swizzle_mask16_to_n32_opaque;
                             break;
                         default:
                             break;
                     }
                     break;
                 case kRGB_565_SkColorType:
-                    switch (dstInfo.alphaType()) {
-                        case kOpaque_SkAlphaType:
-                            proc = &swizzle_mask16_to_565;
-                            break;
-                        default:
-                            break;
-                    }
+                    proc = &swizzle_mask16_to_565;

[scroggo, 2016/02/03 14:58:45]

These changes fix the crash I was seeing on the trybots.

[msarett, 2016/02/03 15:03:07]

Acknowledged.

                     break;
                 default:
                     break;
             }
             break;
         case 24:
             switch (dstInfo.colorType()) {
                 case kN32_SkColorType:
                     switch (dstInfo.alphaType()) {
                         case kUnpremul_SkAlphaType:
                             proc = &swizzle_mask24_to_n32_unpremul;
                             break;
                         case kPremul_SkAlphaType:
                             proc = &swizzle_mask24_to_n32_premul;
                             break;
                         case kOpaque_SkAlphaType:
                             proc = &swizzle_mask24_to_n32_opaque;
                             break;
                         default:
                             break;
                     }
                     break;
                 case kRGB_565_SkColorType:
-                    switch (dstInfo.alphaType()) {
-                        case kOpaque_SkAlphaType:
-                            proc = &swizzle_mask24_to_565;
-                            break;
-                        default:
-                            break;
-                    }
+                    proc = &swizzle_mask24_to_565;
                     break;
                 default:
                     break;
             }
             break;
         case 32:
             switch (dstInfo.colorType()) {
                 case kN32_SkColorType:
                     switch (dstInfo.alphaType()) {
                         case kUnpremul_SkAlphaType:
                             proc = &swizzle_mask32_to_n32_unpremul;
                             break;
                         case kPremul_SkAlphaType:
                             proc = &swizzle_mask32_to_n32_premul;
                             break;
                         case kOpaque_SkAlphaType:
                             proc = &swizzle_mask32_to_n32_opaque;
                             break;
                         default:
                             break;
                     }
                     break;
                 case kRGB_565_SkColorType:
-                    switch (dstInfo.alphaType()) {
-                        case kOpaque_SkAlphaType:
-                            proc = &swizzle_mask32_to_565;
-                            break;
-                        default:
-                            break;
-                    }
+                    proc = &swizzle_mask32_to_565;
                     break;
                 default:
                     break;
             }
             break;
         default:
             SkASSERT(false);
             return nullptr;
     }
 
@@ skipping 37 matching lines @@
 
 /*
  *
  * Swizzle the specified row
  *
  */
 void SkMaskSwizzler::swizzle(void* dst, const uint8_t* SK_RESTRICT src) {
     SkASSERT(nullptr != dst && nullptr != src);
     fRowProc(dst, src, fDstWidth, fMasks, fX0, fSampleX);
 }