linux_aura: Implement file drag and drop in content area.

In OSExchangeData, there's a difference between URLs and files. In the
mime type "text/uri-list", there isn't, and Linux usually uses the later
to exchange both data types.

This fixes dragging files onto several sites, like the HTML Five Wow
Terminal, but doesn't fix Dropbox, which seems to be failing somewhere
else.

BUG=317548

Review URL: https://codereview.chromium.org/129113004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243840 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243840
Autofill popup should not be presented when autocomplete='off', even if
there already is information in the autofill DB.

BUG=326679

Review URL: https://codereview.chromium.org/120343003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243841 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243841