My initial suggestion was to remove this on all platforms:

diff -r 288eb8869c9c modules/graphics/src/main/java/com/sun/prism/es2/ES2Graphics.java
--- a/modules/graphics/src/main/java/com/sun/prism/es2/ES2Graphics.java Wed Oct 23 09:51:45 2013 +0200
+++ b/modules/graphics/src/main/java/com/sun/prism/es2/ES2Graphics.java Wed Oct 23 16:12:25 2013 +0300
@@ -83,7 +83,6 @@
 
     public void sync() {
         context.flushVertexBuffer();
- context.getGLContext().finish();
     }
 
     /**

..but I am not sure this is correct. For desktop platforms we might need this. So this should only be for platforms that use eglfb.