Call rewindIfNeeded in SkCodec

src/codec/SkCodec_libpng.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_libpng.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 459 matching lines @@
     if (!conversion_possible(requestedInfo, this->getInfo())) {
         return kInvalidConversion;
     }
     if (options.fSubset) {
         // Subsets are not supported.
         return kUnimplemented;
     }
     if (requestedInfo.dimensions() != this->getInfo().dimensions()) {
         return kInvalidScale;
     }
-    if (!this->rewindIfNeeded()) {
-        return kCouldNotRewind;
-    }
 
     // Note that ctable and ctableCount may be modified if there is a color table
     const Result result = this->initializeSwizzler(requestedInfo, options,
                                                    ctable, ctableCount);
     if (result != kSuccess) {
         return result;
     }
     // FIXME: Could we use the return value of setjmp to specify the type of
     // error?
     if (setjmp(png_jmpbuf(fPng_ptr))) {
@@ skipping 92 matching lines @@
 public:
     SkPngScanlineDecoder(const SkImageInfo& srcInfo, SkStream* stream,
             png_structp png_ptr, png_infop info_ptr, int bitDepth)
         : INHERITED(srcInfo, stream, png_ptr, info_ptr, bitDepth, 1)
         , fSrcRow(nullptr)
         , fAlphaState(kUnknown_AlphaState)
     {}
 
     Result onStartScanlineDecode(const SkImageInfo& dstInfo, const Options& options,
             SkPMColor ctable[], int* ctableCount) override {
-        if (!this->rewindIfNeeded()) {
-            return kCouldNotRewind;
-        }
-
         if (!conversion_possible(dstInfo, this->getInfo())) {
             return kInvalidConversion;
         }
 
         // Check to see if scaling was requested.
         if (dstInfo.dimensions() != this->getInfo().dimensions()) {
             if (!SkScaledCodec::DimensionsSupportedForSampling(this->getInfo(), dstInfo)) {
                 return kInvalidScale;   
             }
         }
@@ skipping 74 matching lines @@
         , fAlphaState(kUnknown_AlphaState)
         , fHeight(-1)
         , fCanSkipRewind(false)
     {
         SkASSERT(numberPasses != 1);
     }
 
     Result onStartScanlineDecode(const SkImageInfo& dstInfo, const Options& options,
             SkPMColor ctable[], int* ctableCount) override
     {
-        if (!this->rewindIfNeeded()) {
-            return kCouldNotRewind;
-        }
-
         if (!conversion_possible(dstInfo, this->getInfo())) {
             return kInvalidConversion;    
         }
 
         // Check to see if scaling was requested.
         if (dstInfo.dimensions() != this->getInfo().dimensions()) {
             if (!SkScaledCodec::DimensionsSupportedForSampling(this->getInfo(), dstInfo)) {
                 return kInvalidScale;
             }
         }
@@ skipping 130 matching lines @@
 
     if (1 == numberPasses) {
         return new SkPngScanlineDecoder(imageInfo, streamDeleter.detach(), png_ptr, info_ptr,
                                         bitDepth);
     }
 
     return new SkPngInterlacedScanlineDecoder(imageInfo, streamDeleter.detach(), png_ptr,
                                               info_ptr, bitDepth, numberPasses);
 }