Log JumpListUpdater functions' execution time to UMA

Recent UMA data shows that the UpdateJumpList method alone in jumplist.cc
takes 1+ second for more than 1% Canary users. Therefore, it's worthwhile
to investigate all the pieces of this method, which is JumpListUpdater
class related.

BUG=40407, 179576

Review-Url: https://codereview.chromium.org/2818193002
Cr-Commit-Position: refs/heads/master@{#464997}
2 files changed