url: Changes to make it build standalone.

- Update the gyp file.
- Rename the gyp file from googleurl.gyp to url.gyp, so it matches the directory
name.
- Update the header include paths.
- Update the header include guards.
- Rename the target name from googleurl to url and googleurl_unittests to
url_unittests.
- Add missing OVERRIDEs where clang complains.

BUG=229660
TEST=url_unittests
R=brettw@chromium.org

Review URL: https://codereview.chromium.org/14016005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193777 0039d316-1c4b-4281-b951-d872f2087c98
38 files changed