Support wbmp that are supported by SkImageDecoder

src/codec/SkCodec_wbmp.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 "SkCodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 11 matching lines @@
 
 static inline void setup_color_table(SkColorType colorType,
         SkPMColor* colorPtr, int* colorCount) {
     if (kIndex_8_SkColorType == colorType) {
         colorPtr[0] = SK_ColorBLACK;
         colorPtr[1] = SK_ColorWHITE;
         *colorCount = 2;
     }
 }
 
+static bool read_byte(SkStream* stream, uint8_t* data)
+{
+    return stream->read(data, 1) == 1;
+}
+
 // http://en.wikipedia.org/wiki/Variable-length_quantity
 static bool read_mbf(SkStream* stream, uint64_t* value) {
     uint64_t n = 0;
     uint8_t data;
     const uint64_t kLimit = 0xFE00000000000000;
     SkASSERT(kLimit == ~((~static_cast<uint64_t>(0)) >> 7));
     do {
         if (n & kLimit) { // Will overflow on shift by 7.
             return false;
         }
         if (stream->read(&data, 1) != 1) {
             return false;
         }
         n = (n << 7) | (data & 0x7F);
     } while (data & 0x80);
     *value = n;
     return true;
 }
 
 static bool read_header(SkStream* stream, SkISize* size) {
+    {
+        uint8_t data;
+        if (!read_byte(stream, &data) || data != 0) { // unknown type
+            return false;
+        }
+        if (!read_byte(stream, &data) || (data & 0x9F)) { // skip fixed header
+            return false;
+        }
+    }
+
     uint64_t width, height;
-    uint16_t data;
-    if (stream->read(&data, 2) != 2 || data != 0) {
-        return false;
-    }
     if (!read_mbf(stream, &width) || width > 0xFFFF || !width) {
         return false;
     }
     if (!read_mbf(stream, &height) || height > 0xFFFF || !height) {
         return false;
     }
     if (size) {
         *size = SkISize::Make(SkToS32(width), SkToS32(height));
     }
     return true;
@@ skipping 122 matching lines @@
     // Initialize the swizzler
     fSwizzler.reset(this->initializeSwizzler(dstInfo, get_color_ptr(fColorTable.get()), options));
     if (nullptr == fSwizzler.get()) {
         return kInvalidConversion;
     }
 
     fSrcBuffer.reset(fSrcRowBytes);
 
     return kSuccess;
 }