Revert 168080 - Configure system-level Chrome settings (i.e. install its shortcuts) immediately fol…

Revert 168080 - Configure system-level Chrome settings (i.e. install its shortcuts) immediately following self-destruction of a user-level Chrome.

Also refactor RemoveShortcut() to use base::win::ResolveShortcut() instead of coming up with its own method (which I'm scared could still hold handles to the shortcut when trying to delete it; doesn't seem to have been a problem, but I'd rather be safe).

BUG=158524
TEST=Install user-level Chrome on user A, install system-level Chrome on user B (while A is still logged in), go back to user A and run Chrome, user-level Chrome self-destructs and new shortcuts are installed pointing to system-level Chrome.


Review URL: https://chromiumcodereview.appspot.com/11359219

TBR=gab@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=168099