AU: SplitWriter class for parsing our full update files.

src/platform/update_engine/mock_file_writer.h

 // Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H__
 
 #include "base/basictypes.h"
 #include "update_engine/file_writer.h"
 
 // MockFileWriter is an implementation of FileWriter. It will succeed
 // calls to Open(), Close(), but not do any work. All calls to Write()
 // will append the passed data to an internal vector.
 
 namespace chromeos_update_engine {
 
 class MockFileWriter : public FileWriter {
  public:
   MockFileWriter() : was_opened_(false), was_closed_(false) {}
 
   virtual int Open(const char* path, int flags, mode_t mode) {
     CHECK(!was_opened_);
     CHECK(!was_closed_);
     was_opened_ = true;
     return 0;
   }
 
-  virtual int Write(const void* bytes, size_t count) {
+  virtual ssize_t Write(const void* bytes, size_t count) {
     CHECK(was_opened_);
     CHECK(!was_closed_);
     const char* char_bytes = reinterpret_cast<const char*>(bytes);
     bytes_.insert(bytes_.end(), char_bytes, char_bytes + count);
     return count;
   }
 
   virtual int Close() {
     CHECK(was_opened_);
     CHECK(!was_closed_);
@@ skipping 11 matching lines @@
   // These are just to ensure FileWriter methods are called properly.
   bool was_opened_;
   bool was_closed_;
 
   DISALLOW_COPY_AND_ASSIGN(MockFileWriter);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H__