Review request for 6612680 (Remove classloader dependency on jkernel)

[Mandy Chung]

Alan, Karen,

Can you review the fix for:
    6612680: Remove classloader dependency on jkernel

Webrev at:
   http://cr.openjdk.java.net/~mchung/6612680/

java.lang.ClassLoader and sun.misc.Launcher have explicit dependencies 
on the jkernel code.  While the performance impact of this is minimal 
(the calls basically amount to nops when the JRE is complete), it's 
still undesirable.

To eliminate the static dependency on jkernel, this adds a boot 
classloader hook interface that is invoked in the ClassLoader findClass, 
getSystemResource, and other methods.  The hook is null by default.  The 
jkernel VM will call the static  
DownloadManager.setBootClassLoaderHook() method and only the jkernel 
environment will have a non-null boot class loader hook.  Since jkernel 
is a separate build including the bundles and VM, as we discussed, the 
jkernel VM is a reasonable place to inject the DownloadManager as the 
boot class loader hook.

I'm hoping to make TL b74 which is code freeze by 10 pm PT Monday.

Thanks
Mandy