Change SkImageDecoders to take an SkStreamRewindable.

src/utils/win/SkIStream.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #define WIN32_LEAN_AND_MEAN
@@ skipping 158 matching lines @@
         this->fLocation.QuadPart += skipped;
         if (skipped != liDistanceToMove.QuadPart) {
             hr = E_FAIL;
         }
         break;
     }
     case STREAM_SEEK_END: {
         if (!this->fSkStream->rewind()) {
             hr = E_FAIL;
         } else {
+            // FIXME: Should not depend on getLength.
+            // See https://code.google.com/p/skia/issues/detail?id=1570
             LONGLONG skip = this->fSkStream->getLength()
                           + liDistanceToMove.QuadPart;
             size_t skipped = this->fSkStream->skip(static_cast<size_t>(skip));
             this->fLocation.QuadPart = skipped;
             if (skipped != skip) {
                 hr = E_FAIL;
             }
         }
         break;
     }
     default:
         hr = STG_E_INVALIDFUNCTION;
         break;
     }
 
     if (NULL != lpNewFilePointer) {
         lpNewFilePointer->QuadPart = this->fLocation.QuadPart;
     }
     return hr;
 }
 
 HRESULT STDMETHODCALLTYPE SkIStream::Stat(STATSTG* pStatstg
                                         , DWORD grfStatFlag)
 {
     if (0 == (grfStatFlag & STATFLAG_NONAME)) {
         return STG_E_INVALIDFLAG;
     }
     pStatstg->pwcsName = NULL;
+    // FIXME: Should not depend on getLength
+    // See https://code.google.com/p/skia/issues/detail?id=1570
     pStatstg->cbSize.QuadPart = this->fSkStream->getLength();
     pStatstg->clsid = CLSID_NULL;
     pStatstg->type = STGTY_STREAM;
     pStatstg->grfMode = STGM_READ;
     return S_OK;
 }
 
 
 /**
  * SkIWStream
@@ skipping 44 matching lines @@
     if (0 == (grfStatFlag & STATFLAG_NONAME)) {
         return STG_E_INVALIDFLAG;
     }
     pStatstg->pwcsName = NULL;
     pStatstg->cbSize.QuadPart = 0;
     pStatstg->clsid = CLSID_NULL;
     pStatstg->type = STGTY_STREAM;
     pStatstg->grfMode = STGM_WRITE;
     return S_OK;
 }