Mac: Add IME support with off-screen rendering (issue #973).

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk@1259 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
Use scoped class to implement CEF_TRACE_EVENTx (issue #971).

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk@1261 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
Add CefJSDialogHandler::OnDialogClosed callback (issue #943).

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk@1263 5089003a-bbd8-11dd-ad1f-f1f9622dbc98