Reland: Password manager: Gnome support for Public Suffix List matching

This CL:

* Fixes a memory leak of the previous attempt at https://codereview.chromium.org/123223003
* Enables Public Suffix List (PSL) general utilities on Linux.
* Enables PSL flag for Linux.
* Adds Gnome Keyring support for searching and filtering multiple origins, including UMA metrics and a unit test.

The first patch set is identical to https://codereview.chromium.org/123223003, so that the fix of the leak can be viewed by diffing against that.

TBR=gcasto@chromium.org
BUG=324291

Review URL: https://codereview.chromium.org/134303003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244494 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244494