Support more swizzles to 565 in SkCodec

src/codec/SkBmpCodec.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 "SkBmpCodec.h"
 #include "SkBmpMaskCodec.h"
 #include "SkBmpRLECodec.h"
@@ skipping 379 matching lines @@
         // V3+, we are guaranteed to be able to read at least this size.
         SkASSERT(infoBytesRemaining > 52);
         inputMasks.alpha = get_int(iBuffer.get(), 48);
         if (inputMasks.alpha != 0) {
             alphaType = kUnpremul_SkAlphaType;
         }
     }
     iBuffer.free();
 
     // Additionally, 32 bit bmp-in-icos use the alpha channel.
+    // FIXME (msarett): Don't all bmp-in-icos use the alpha channel?
     // And, RLE inputs may skip pixels, leaving them as transparent.  This
     // is uncommon, but we cannot be certain that an RLE bmp will be opaque.
     if ((inIco && 32 == bitsPerPixel) || (kRLE_BmpInputFormat == inputFormat)) {
         alphaType = kUnpremul_SkAlphaType;
     }
 
     // Check for valid bits per pixel.
     // At the same time, use this information to choose a suggested color type
     // and to set default masks.
     SkColorType colorType = kN32_SkColorType;
@@ skipping 145 matching lines @@
  */
 uint32_t SkBmpCodec::computeNumColors(uint32_t numColors) {
     // Zero is a default for maxColors
     // Also set numColors to maxColors when it is too large
     uint32_t maxColors = 1 << fBitsPerPixel;
     if (numColors == 0 || numColors >= maxColors) {
         return maxColors;
     }
     return numColors;
 }