LoadTiming int net 6:  Cache LoadTimingInfo

LoadTiming information is now cached at the URLRequest
level, so it can be read at any point after the headers
are received, until/unless the request is restarted.

The old behavior of keeping the information only as long as
it could be retrieved resulted in some problems.
Review URL: https://codereview.chromium.org/12114052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@180243 0039d316-1c4b-4281-b951-d872f2087c98
6 files changed