Split infobars.{cc,h} into separate pieces for the different classes defined within, so that each piece is shorter and clearer.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/6250057

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@73235 0039d316-1c4b-4281-b951-d872f2087c98
BeforeTranslateInfoBar::~BeforeTranslateInfoBar() {
}

BeforeTranslateInfoBar::~BeforeTranslateInfoBar() {
}
