Wait for renaming chrome.exe to finish during shutdown for system level in use update. Also remove obsoleted code in this code path.
Wait for renaming chrome.exe to finish during shutdown for
system level in use update.
Also remove obsoleted code in this code path.

BUG=55969
TEST=repro steps in BUG

Review URL: http://codereview.chromium.org/3429029

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@60751 0039d316-1c4b-4281-b951-d872f2087c98

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