Add support for multiple frames in SkCodec

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 "SkBmpCodec.h"
 #include "SkCodec.h"
 #include "SkCodecPriv.h"
@@ skipping 124 matching lines @@
     , fNeedsRewind(false)
     , fOrigin(origin)
     , fDstInfo()
     , fOptions()
     , fCurrScanline(-1)
 {}
 
 SkCodec::~SkCodec() {}
 
 bool SkCodec::rewindIfNeeded() {
-    if (!fStream) {
-        // Some codecs do not have a stream.  They may hold onto their own data or another codec.
-        // They must handle rewinding themselves.
-        return true;
-    }
-
     // Store the value of fNeedsRewind so we can update it. Next read will
     // require a rewind.
     const bool needsRewind = fNeedsRewind;
     fNeedsRewind = true;
     if (!needsRewind) {
         return true;
     }
 
     // startScanlineDecode will need to be called before decoding scanlines.
     fCurrScanline = -1;
     // startIncrementalDecode will need to be called before incrementalDecode.
     fStartedIncrementalDecode = false;
 
-    if (!fStream->rewind()) {
+    // Some codecs do not have a stream.  They may hold onto their own data or another codec.
+    // They must handle rewinding themselves.
+    if (fStream && !fStream->rewind()) {
         return false;
     }
 
     return this->onRewind();
 }
 
 #define CHECK_COLOR_TABLE                                   \
     if (kIndex_8_SkColorType == info.colorType()) {         \
         if (nullptr == ctable || nullptr == ctableCount) {  \
             return SkCodec::kInvalidParameters;             \
@@ skipping 290 matching lines @@
             fillDst = SkTAddOffset<void>(dst, linesDecoded * rowBytes);
             fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
             break;
         }
         case kBottomUp_SkScanlineOrder: {
             fillDst = dst;
             const SkImageInfo fillInfo = info.makeWH(fillWidth, linesRemaining);
             fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
             break;
         }
-        case kOutOfOrder_SkScanlineOrder: {
-            SkASSERT(1 == linesRequested || this->getInfo().height() == linesRequested);
-            const SkImageInfo fillInfo = info.makeWH(fillWidth, 1);
-            for (int srcY = linesDecoded; srcY < linesRequested; srcY++) {
-                fillDst = SkTAddOffset<void>(dst, this->outputScanline(srcY) * rowBytes);
-                fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
-            }
-            break;
-        }
     }
 }