Modify the password manager frontend to call into C++ every time the user
wants to reveal a plaintext password.

BUG=302296
R=bauerb@chromium.org

Review URL: https://codereview.chromium.org/25463002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226215 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226215
Delete IBusInputContextClient

IBusInputContextClient is no longer used in the production at all.

BUG=275262

Review URL: https://codereview.chromium.org/25081003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226216 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226216