Change extension id format back to mp-decimal, and change the
length to 32 chars (exactly 128 bits).

Review URL: http://codereview.chromium.org/126074

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18351 0039d316-1c4b-4281-b951-d872f2087c98
40 files changed