fix WBMP image will get null color table when draw in RGB565 Canvas

src/images/SkImageDecoder_wbmp.cpp

 
 /*
  * 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.
  */
 
 
 #include "SkImageDecoder.h"
@@ skipping 101 matching lines @@
     int height = head.fHeight;
 
     decodedBitmap->setInfo(SkImageInfo::Make(width, height,
                                              kIndex_8_SkColorType, kOpaque_SkAlphaType));
 
     if (SkImageDecoder::kDecodeBounds_Mode == mode) {
         return true;
     }
 
     const SkPMColor colors[] = { SK_ColorBLACK, SK_ColorWHITE };
-    SkColorTable* ct = SkNEW_ARGS(SkColorTable, (colors, 2));
+    SkColorTable* ct = SkNEW_ARGS(SkColorTable, (colors, 2, kOpaque_SkAlphaType));
     SkAutoUnref   aur(ct);
 
     if (!this->allocPixelRef(decodedBitmap, ct)) {
         return false;
     }
 
     SkAutoLockPixels alp(*decodedBitmap);
 
     uint8_t* dst = decodedBitmap->getAddr8(0, 0);
     // store the 1-bit valuess at the end of our pixels, so we won't stomp
@@ skipping 31 matching lines @@
 static SkImageDecoder::Format get_format_wbmp(SkStreamRewindable* stream) {
     wbmp_head head;
     if (head.init(stream)) {
         return SkImageDecoder::kWBMP_Format;
     }
     return SkImageDecoder::kUnknown_Format;
 }
 
 static SkImageDecoder_DecodeReg gDReg(sk_wbmp_dfactory);
 static SkImageDecoder_FormatReg gFormatReg(get_format_wbmp);