During installer cleanup, replace the use of rollback-able DeleteTreeWorkItems with simple deletes, since we don't care to rollback the attempts to delete our temp files. This avoids a redundant copy and deletion of the temp files.
During installer cleanup, replace the use of rollback-able DeleteTreeWorkItems with simple deletes, since we don't care to rollback the attempts to delete our temp files. This avoids a redundant copy and deletion of the temp files.

BUG=25878
TEST=Chrome / Chrome Frame installer spends less time between the verbose log traces "Deleting temporary directory" and "list execution succeeded".

Review URL: http://codereview.chromium.org/2870066

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@53469 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser