[net/base] Forward declaration of classes instead of including header

Forward declaration of class instead of including header in net/base as per chromium's guidelines
https://www.chromium.org/developers/coding-style/cpp-dos-and-donts#TOC-Forward-declare-classes-instead-of-including-headers.

Committed: https://crrev.com/3cd0301c2d6a3a59c22db36be6df9ec004d6d6a4
Cr-Commit-Position: refs/heads/master@{#330708}

[Pranay, 2015-05-19 13:15:33]

pranay.kumar@samsung.com changed reviewers:
+ mmenke@chromium.org

[Pranay, 2015-05-19 13:15:34]

Hi PTAL

Thanks

[mmenke, 2015-05-19 14:45:16]

LGTM!

https://codereview.chromium.org/1135793006/diff/1/net/base/directory_lister.cc
File net/base/directory_lister.cc (right):

https://codereview.chromium.org/1135793006/diff/1/net/base/directory_lister.c...
net/base/directory_lister.cc:14: #include "base/message_loop/message_loop.h"
While you're here, I believe you can remove this header - doesn't look like
MessageLoop is currently used in this file.

[Pranay, 2015-05-20 03:09:35]

https://codereview.chromium.org/1135793006/diff/1/net/base/directory_lister.cc
File net/base/directory_lister.cc (right):

https://codereview.chromium.org/1135793006/diff/1/net/base/directory_lister.c...
net/base/directory_lister.cc:14: #include "base/message_loop/message_loop.h"
This file has FROM_HERE flag ( dependency - base/location.h) which is included
in message_loop.h that's why we will need to include location.h after removing
messsage_loop.h ..Done

[Pranay, 2015-05-20 05:31:31]

The CQ bit was checked by pranay.kumar@samsung.com

[Pranay, 2015-05-20 05:31:31]

The patchset sent to the CQ was uploaded after l-g-t-m from mmenke@chromium.org
Link to the patchset: https://codereview.chromium.org/1135793006/#ps20001
(title: "Fixed Review Comments")

[commit-bot: I haz the power, 2015-05-20 05:31:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1135793006/20001

[Pranay, 2015-05-20 07:11:54]

The CQ bit was unchecked by pranay.kumar@samsung.com

[commit-bot: I haz the power, 2015-05-20 07:12:02]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-20 07:13:22]

Patchset 2 (id:??) landed as
https://crrev.com/3cd0301c2d6a3a59c22db36be6df9ec004d6d6a4
Cr-Commit-Position: refs/heads/master@{#330708}