Clean up test-info.json.

 - Remove "code" section from all Telemetry benchmarks. This is not used by the dashboard, and would be redundant since the benchmark name is encoded in the test suite name.
 - Alphabetize test suites.
 - Remove startup_test and startup_measurement, which I believe are not running anymore?

BUG=

Review URL: https://codereview.chromium.org/34003002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230076 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230076