Reland of: Split out InputMethodMenuManager from InputMethodManager.

Rename input_method_property to input_method_menu_item, and move to ash/ime.

This is a reland of https://codereview.chromium.org/150203015,reverted by https://codereview.chromium.org/165453002

Use Singleton<> instead of trying to maintain my own singleton.

BUG=342336, 343044

Review URL: https://codereview.chromium.org/165783002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251327 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251327
Cleanup: Remove WebFormElement include from autofill_manager_unittest.cc

Apparently this type is not used by the unit tests and allow us to
remove another entry from the DEPS file.

BUG=140037
TEST=unit_tests
R=joi@chromium.org,blundell@chromium.org

Review URL: https://codereview.chromium.org/165453003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251328 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251328