drive: Add the local largest changestamp to chrome:drive-internals
This information would be useful to invetigate issues where the local
file system metadata is out of sync.
Along the way, replace SetString() with SetDouble() for the largest
changestamp values. The largest change stamp should be small enough to
fit in double without losing precision.
BUG=155473
TEST="Largetst Changestamp (local)" is added in chrome:drive-internals
Review URL: https://chromiumcodereview.appspot.com/11106009
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@162118 0039d316-1c4b-4281-b951-d872f2087c98
7 files changed
