Extensions: Don't pass the selected unpacked extension path from JS to C++
handler.

This is an unecessary hoop to jump through since the C++ is the original
callback of the file dialog.

BUG=117715
TEST=none
TBR=sky
R=csilv,aa


Review URL: http://codereview.chromium.org/9703039

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@128801 0039d316-1c4b-4281-b951-d872f2087c98
8 files changed