Files.app: Prevent the second window from launching when pressing the shortcut key repeatedly.

When pressing the shortcut key, ChromeShellDelegate obtains the list
of the application window from ShellWindowRegistry. Previously if the shortcut key is
pressed twice quickly, before the first application window launches and is
registed to ShellWindowRegistry, the second application window is requested to
launch because ShellWindowRegistry returned an empty list at that time.

This CL introduces FileManagerLaunchHelper to manage the launching state and
prevents an application window launching while another window is launching.

BUG=308398
TEST=manually

Review URL: https://codereview.chromium.org/27673002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231325 0039d316-1c4b-4281-b951-d872f2087c98
Use the loaded bounds before applying size constraint.

BUG=310868

Review URL: https://codereview.chromium.org/41963003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231326 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231325
SVN changes up to revision 231326