Clean up in ipc_channel_posix.

This changes around our handling of file descriptors to reduce code duplication and increase clarity. I tried to minimize actual changes and just move code. There are a few exceptions:

The input file descriptor buffer is now a deque rather than a complicated fixed size buffer with extra overflow. This greatly simplifies some code. In practice, I don't think this will change the number of allocations we do in a practical way.

I changed a few logging statements that seemed relevant to IPC developers only into the "D" variants.

The msghdr struct used to be declared once at the top of ProcessOutgoingMessages and re-used for all calls to recvmsg. Now that the different callers are split out into sub functions, there is more initialization of the msghdr structs used in this call. I don't think this will be significant.


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=124272

[Elliot Glaysher, 2012-02-29 18:25:58]

lgtm

(I wish that had been two patches, one to factor stuff out into functions, and
one to change the data structures.)

[commit-bot: I haz the power, 2012-02-29 20:12:47]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/brettw@chromium.org/9533002/5001

[commit-bot: I haz the power, 2012-02-29 22:48:19]

Change committed as 124272