Add dependency on libevent where required.

Add dependency on libevent where required.

Otherwise some portions of the code try to use
bundled libevent headers instead of the system-provided
ones if -Duse_system_libevent=1 is used.

TEST=none
BUG=none

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=49634

[Paweł Hajdan Jr., 2010-06-10 17:04:23]

I've discovered the issue while working on an updated package for Gentoo Linux,
that removes completely some bundled libraries to ensure they are not used.

[Evan Martin, 2010-06-10 17:23:47]

http://codereview.chromium.org/2729012/diff/1/2
File chrome/chrome.gyp (right):

http://codereview.chromium.org/2729012/diff/1/2#newcode477
chrome/chrome.gyp:477: '../third_party/libevent/libevent.gyp:libevent',
Does this use libevent directly?  Or does it depend on another library that
depends on libevent?  It seems more likely it's the latter, no?  We should fix
that library in that case, I think.

[Paweł Hajdan Jr., 2010-06-10 17:28:44]

http://codereview.chromium.org/2729012/diff/1/2
File chrome/chrome.gyp (right):

http://codereview.chromium.org/2729012/diff/1/2#newcode477
chrome/chrome.gyp:477: '../third_party/libevent/libevent.gyp:libevent',
On 2010/06/10 17:23:48, Evan Martin wrote:
> Does this use libevent directly?  Or does it depend on another library that
> depends on libevent?  It seems more likely it's the latter, no?  We should fix
> that library in that case, I think.

Yes, it uses libevent directly. See devtools_remote_listen_socket.cc.

[Evan Martin, 2010-06-10 17:42:28]

Does this really use libevent directly?  I see the #include but I don't see why
it's needed.  I am really confused.

[apavlov, 2010-06-11 10:02:59]

On 2010/06/10 17:42:28, Evan Martin wrote:
> Does this really use libevent directly?  I see the #include but I don't see
why
> it's needed.  I am really confused.

This #include really looks unnecessary, my apologies. The class was initially
presumed to be a fork of ListenSocket (not derived from one), and as such, it
may have retained some odd includes.
Today is my last workday before the vacation, so I won't be able to provide more
info shortly :(

[Paweł Hajdan Jr., 2010-06-11 10:06:45]

Patch updated, please take another look.

[apavlov, 2010-06-11 10:09:15]

LGTM

Thanks a lot for handling this! Hope it builds fine :)

[Evan Martin, 2010-06-11 14:43:43]

I still wonder if there's a single shared place to depend on libevent, but it
seems plausible to me that net might reach into it from multiple libraries. 
LGTM if you promise you verified that these dependencies are necessary.  :)