linux_aura: Call Env::CreateInstance() earlier in chrome_browser_main.cc.

This needs to happen before we create a profile because profiles can
bring up error message dialogs.

BUG=317974
R=ben@chromium.org

Review URL: https://codereview.chromium.org/72133002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235227 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235227