Files.app: Change when to send BEGIN progress event.

Previously tasks of FileOperationManager is queued and the BEGIN progress event
is sent when the task reaches to the top of the queue.  But currently we can
show the multiple tasks by using ProgressCenter.  This CL let
FileOperationManager send the BEGIN event when the task is added to the queue.

BUG=277432
TEST=manually

Review URL: https://codereview.chromium.org/36603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230675 0039d316-1c4b-4281-b951-d872f2087c98
Enable to animate InputMethodContainer.

Without this change, views::corewm::SetWindowVisibilityAnimationType in ModeIndicatorWidget does not work as expected.

BUG=177765

Review URL: https://codereview.chromium.org/37023002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230676 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230676