If Firefox is not installed, the DT plugin is not getting registered with Chrome during JRE7 installation.

IF Firefox is installed then Chrome will find it in the Firefox plugins but we can not expect Chrome users
will have Firefox installed too.
This fix is rather localized/scope-restricted. Simple to test/verify as well a low risk and high impact for the client side: fine grain jre version detection in the Chrome platform is really required as this platform is ever growing in the market.
Pls approve.