Add the enable-ime-mode-indicator option.

BUG=177765

Review URL: https://codereview.chromium.org/24324008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225500 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225500
Remove ipc::CommandBufferProxy. As an interface, it's not used.

BUG=None

Review URL: https://codereview.chromium.org/24483008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225501 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225501