Update DirectWrite streams to SkStreamAsset.

src/utils/win/SkDWriteFontFileStream.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTypes.h"
 #include "SkDWriteFontFileStream.h"
 #include "SkHRESULT.h"
@@ skipping 115 matching lines @@
     UINT64 fileSize;
     HRNM(fFontFileStream->GetFileSize(&fileSize), "Could not get file size");
     HRNM(fFontFileStream->ReadFileFragment(&fLockedMemory, 0, fileSize, &fFragmentLock),
          "Could not lock file fragment.");
     return fLockedMemory;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 //  SkIDWriteFontFileStreamWrapper
 
-HRESULT SkDWriteFontFileStreamWrapper::Create(SkStream* stream, SkDWriteFontFileStreamWrapper** streamFontFileStream) {
+HRESULT SkDWriteFontFileStreamWrapper::Create(SkStreamAsset* stream,
+                                              SkDWriteFontFileStreamWrapper** streamFontFileStream)
+{
     *streamFontFileStream = new SkDWriteFontFileStreamWrapper(stream);
     if (NULL == streamFontFileStream) {
         return E_OUTOFMEMORY;
     }
     return S_OK;
 }
 
-SkDWriteFontFileStreamWrapper::SkDWriteFontFileStreamWrapper(SkStream* stream)
+SkDWriteFontFileStreamWrapper::SkDWriteFontFileStreamWrapper(SkStreamAsset* stream)
     : fRefCount(1), fStream(stream) {
 }
 
 HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::QueryInterface(REFIID iid, void** ppvObject) {
     if (iid == IID_IUnknown || iid == __uuidof(IDWriteFontFileStream)) {
         *ppvObject = this;
         AddRef();
         return S_OK;
     } else {
         *ppvObject = NULL;
@@ skipping 31 matching lines @@
     if (!SkTFitsIn<size_t>(fileOffset + fragmentSize)) {
         return E_FAIL;
     }
 
     const void* data = fStream->getMemoryBase();
     if (data) {
         *fragmentStart = static_cast<BYTE const*>(data) + static_cast<size_t>(fileOffset);
         *fragmentContext = NULL;
 
     } else {
-        //May be called from multiple threads.
+        // May be called from multiple threads.
         SkAutoMutexAcquire ama(fStreamMutex);
 
         *fragmentStart = NULL;
         *fragmentContext = NULL;
 
-        if (!fStream->rewind()) {
-            return E_FAIL;
-        }
-        if (fStream->skip(static_cast<size_t>(fileOffset)) != fileOffset) {
+        if (!fStream->seek(static_cast<size_t>(fileOffset))) {
             return E_FAIL;
         }
         SkAutoTMalloc<uint8_t> streamData(static_cast<size_t>(fragmentSize));
         if (fStream->read(streamData.get(), static_cast<size_t>(fragmentSize)) != fragmentSize) {
             return E_FAIL;
         }
 
         *fragmentStart = streamData.get();
         *fragmentContext = streamData.detach();
     }
     return S_OK;
 }
 
 void STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::ReleaseFileFragment(void* fragmentContext) {
     sk_free(fragmentContext);
 }
 
 HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::GetFileSize(UINT64* fileSize) {
     *fileSize = fStream->getLength();
     return S_OK;
 }
 
 HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::GetLastWriteTime(UINT64* lastWriteTime) {
     // The concept of last write time does not apply to this loader.
     *lastWriteTime = 0;
     return E_NOTIMPL;
 }