Add net/ to PRESUBMIT.py whitelist to check for base::string16.

R=maruel@chromium.org
BUG=329295
NOTRY=true

Review URL: https://codereview.chromium.org/102073009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241594 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241594
Revert 241574 "Add libc++ and libc++abi to third-party."

[Reason for revert: linux builder check_licenses failure. - nick]

> Add libc++ and libc++abi to third-party.
> 
> BUG=318770, 313751
> R=glider@chromium.org,thakis@chromium.org,bradnelson@chromium.org,darin@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=240682
> 
> Review URL: https://codereview.chromium.org/75213003

TBR=alextaran@chromium.org

Review URL: https://codereview.chromium.org/118243004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241595 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241596 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241596