Record chrome's startup time, to be used in future retention experiments

- For windows in the registry
- not implemented for posix

BUG=32474
TEST=none


Review URL: http://codereview.chromium.org/558009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@37360 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed