Add HTTPBodyStream interface, three concrete implementations, and their tests.

util/file/fd_io.h

Index: util/file/fd_io.h
diff --git a/util/file/fd_io.h b/util/file/fd_io.h
index 14481c93752c6fcec8e25566f37c5ea484017341..42d9f04dde30446e3cabc14d8c906f86791dfe6b 100644
--- a/util/file/fd_io.h
+++ b/util/file/fd_io.h
@@ -79,6 +79,12 @@ void CheckedWriteFD(int fd, const void* buffer, size_t size);
 //! \sa ReadFD
 void CheckedReadFDAtEOF(int fd);
 
+//! \brief Wraps `close()`, logging an error if the operation fails.
+//!
+//! \return On success, `0` is returned. On failure, an error is logged and

[Mark Mentovai, 2014/10/24 17:46:58]

Map this to a bool?

[Robert Sesek, 2014/10/24 18:45:31]

Done.

+//!     `-1` is returned.
+int CloseFD(int fd);

[Mark Mentovai, 2014/10/24 17:46:58]

I’m a little troubled by the fact that you’d conceptually think that ReadFD and
WriteFD go with CloseFD, but CloseFD is the only one of the three that logs on
error.

CheckedCloseFD would obviously PCHECK and that goes with CheckedRead/WriteFD,
but if you don’t want a CHECKing variant, maybe the best way to resolve this is
to give it a different name. LoggingCloseFD?

[Robert Sesek, 2014/10/24 18:45:31]

Yea, that bothered me too. Renamed to LoggingCloseFD().

+
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_FILE_FD_IO_H_