Start sending synthetic keyevents for enter and tab in Android IME

After sdk 15 Android framework no longer sends keyevents for enter and tab
and the current spec says the dispatchKeyEvent call should only be used for
hardware keyboard. So we stop calling ImeAdapter with dispathKeyEvent if the
keyboard is not connected and also start sending these keyevents when a
they are committed as a single character

BUG=166233


Review URL: https://chromiumcodereview.appspot.com/11914003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@177774 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed