Refactor FFmpegURLProtocol code from FFmpegDemuxer into BlockingUrlProtocol.

media/filters/file_data_source.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/file_data_source.h"
 
 #include <limits>
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 
 namespace media {
 
 FileDataSource::FileDataSource()
     : file_(NULL),
       file_size_(0),
-      disable_file_size_(false) {
-}
-
-FileDataSource::FileDataSource(bool disable_file_size)
-    : file_(NULL),
-      file_size_(0),
-      disable_file_size_(disable_file_size) {
+      force_read_errors_(false),
+      force_streaming_(false) {
 }
 
 bool FileDataSource::Initialize(const std::string& url) {
   DCHECK(!file_);
 #if defined(OS_WIN)
   FilePath file_path(UTF8ToWide(url));
 #else
   FilePath file_path(url);
 #endif
   if (file_util::GetFileSize(file_path, &file_size_)) {
@@ skipping 21 matching lines @@
     file_size_ = 0;
   }
   if (!callback.is_null())
     callback.Run();
 }
 
 void FileDataSource::Read(int64 position, int size, uint8* data,
                           const DataSource::ReadCB& read_cb) {
   DCHECK(file_);
   base::AutoLock l(lock_);
-  if (file_) {
+
+  if (!force_read_errors_ && file_) {
 #if defined(OS_WIN)
     if (_fseeki64(file_, position, SEEK_SET)) {
       read_cb.Run(DataSource::kReadError);
       return;
     }
 #else
     CHECK(position <= std::numeric_limits<int32>::max());
     // TODO(hclam): Change fseek() to support 64-bit position.
     if (fseek(file_, static_cast<int32>(position), SEEK_SET)) {
       read_cb.Run(DataSource::kReadError);
       return;
     }
 #endif
     int size_read = fread(data, 1, size, file_);
     if (size_read == size || !ferror(file_)) {
       read_cb.Run(size_read);
       return;
     }
   }
 
   read_cb.Run(kReadError);
 }
 
 bool FileDataSource::GetSize(int64* size_out) {
   DCHECK(size_out);
   DCHECK(file_);
   base::AutoLock l(lock_);
   *size_out = file_size_;
-  return (NULL != file_ && !disable_file_size_);
+  return file_;
 }
 
 bool FileDataSource::IsStreaming() {
-  return false;
+  return force_streaming_;
 }
 
 void FileDataSource::SetBitrate(int bitrate) {}
 
 FileDataSource::~FileDataSource() {
   DCHECK(!file_);
 }
 
 void FileDataSource::UpdateHostBytes() {
   if (host() && file_) {
     host()->SetTotalBytes(file_size_);
     host()->AddBufferedByteRange(0, file_size_);
   }
 }
 
 }  // namespace media