Improve error handling in the process library.

runtime/bin/file.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef BIN_FILE_H_
 #define BIN_FILE_H_
 
 #if defined(_WIN32)
 typedef signed __int64 int64_t;
 typedef unsigned __int8 uint8_t;
 #else
 #include <stdint.h>
 #endif
 
-#include <assert.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <sys/types.h>
 
 // Forward declaration.
 class FileHandle;
 
 class File {
  public:
@@ skipping 43 matching lines @@
   const char* name_;
   // FileHandle is an OS specific class which stores data about the file.
   FileHandle* handle_;  // OS specific handle for the file.
 
   // DISALLOW_COPY_AND_ASSIGN(File).
   File(const File&);
   void operator=(const File&);
 };
 
 #endif  // BIN_FILE_H_