Revert 236746 "Files.app: Enable VolumeManager to find a volume ..."

> Files.app: Enable VolumeManager to find a volume by using any paths.
> 
> Currently VolumeManager can find a volume by using only mount paths.  But after
> introducing the multiprofile functionality, mount paths cannot be expected in
> advance. This CL enables the getVolume method of VolumeManager to find a volume by
> using any paths.
> 
> BUG=302090
> TEST=manually
> 
> Review URL: https://codereview.chromium.org/64753005

TBR=hirono@chromium.org

Review URL: https://codereview.chromium.org/84133005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237034 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237034