SkCodec: add wbmp class

src/codec/SkCodec.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 "SkData.h"
 #include "SkCodec_libbmp.h"
 #include "SkCodec_libico.h"
 #include "SkCodec_libpng.h"
+#include "SkCodec_wbmp.h"
 #include "SkStream.h"
 
 struct DecoderProc {
     bool (*IsFormat)(SkStream*);
     SkCodec* (*NewFromStream)(SkStream*);
 };
 
 static const DecoderProc gDecoderProcs[] = {
     { SkPngCodec::IsPng, SkPngCodec::NewFromStream },
     { SkIcoCodec::IsIco, SkIcoCodec::NewFromStream },
-    { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream }
+    { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream },
+    { SkWbmpCodec::IsWbmp, SkWbmpCodec::NewFromStream }
 };
 
 SkCodec* SkCodec::NewFromStream(SkStream* stream) {
     if (!stream) {
         return NULL;
     }
     for (uint32_t i = 0; i < SK_ARRAY_COUNT(gDecoderProcs); i++) {
         DecoderProc proc = gDecoderProcs[i];
         const bool correctFormat = proc.IsFormat(stream);
         if (!stream->rewind()) {
@@ skipping 15 matching lines @@
 
 SkCodec::SkCodec(const SkImageInfo& info, SkStream* stream)
     : INHERITED(info)
 #ifdef SK_SUPPORT_LEGACY_BOOL_ONGETINFO
     , fInfo(info)
 #endif
     , fStream(stream)
     , fNeedsRewind(false)
 {}
 
-bool SkCodec::rewindIfNeeded() {
+SkCodec::RewindState SkCodec::rewindIfNeeded() {
     // Store the value of fNeedsRewind so we can update it. Next read will
     // require a rewind.
-    const bool neededRewind = fNeedsRewind;
+    const bool needsRewind = fNeedsRewind;
     fNeedsRewind = true;
-    return !neededRewind || fStream->rewind();
+    if (!needsRewind) {
+        return kNoRewindNecessary_RewindState;
+    }
+    return fStream->rewind() ? kRewound_RewindState
+                             : kCouldNotRewind_RewindState;
 }
 
 SkScanlineDecoder* SkCodec::getScanlineDecoder(const SkImageInfo& dstInfo) {
     fScanlineDecoder.reset(NULL);
     if (!rewindIfNeeded()) {
         return NULL;
     }
     fScanlineDecoder.reset(this->onGetScanlineDecoder(dstInfo));
     return fScanlineDecoder.get();
 }