[8u] RFR: JDK-8212139: FX 8u-dev fails to build on Oracle Linux 6 after fix for JDK-8206246

[Kevin Rushforth]

Phil,

Please review the following:

https://bugs.openjdk.java.net/browse/JDK-8212139
http://cr.openjdk.java.net/~kcr/8212139/webrev/

The recently-pushed GTK3 update for JDK-8206246 [1] has caused a fatal 
build failure on our production Linux build machines. Please review the 
following webrev, which backs out JDK-8206246 using "hg backout":

The production builds of FX 8u are done on an Oracle Linux 6 machine, 
which doesn't have the needed libraries for GTK 3. We need to explore 
upgrading to Oracle Linux 7, but in the mean time we need to backout 
this change.

Sorry for the trouble. We will look at getting this back in as soon as 
we can.

-- Kevin

[1] https://bugs.openjdk.java.net/browse/JDK-8206246