Pass profile into InputMethodEventRouter instead of using GetDefaultProfile

Also, use BrowserContext instead of Profile.

BUG=322682
TEST=None

Review URL: https://codereview.chromium.org/99133008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240075 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240075