Fix silent import from file during install.
Fix silent import from file during install.

Regression was caused by changes made for
http://code.google.com/p/chromium/issues/detail?id=40975.
The change broke first run import 
http://code.google.com/p/chromium/issues/detail?id=41077.
A fix is made but there is a bug in the fix.

BUG=46763
TEST=mini_installer.exe --installerdata="path"


Review URL: http://codereview.chromium.org/2820014

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@50379 0039d316-1c4b-4281-b951-d872f2087c98

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