Performance benchmark Surface shows max memory usage increase on each test iteration.
Performance (fps) was also dropped, this is perhaps related to extra GC time.

Running Surface benchmark with big number of iterations fails with OutOfMemory error.
Heap dump file analysis shows that PhongMaterial objects (which are created on each iterations)
are not removed and kept alive.

For example running the benchmark with 64mg of heap fails after 11 iterations.
In case of 96mg the test fails after 19 iterations.

The issue is first observed in build 8.0-graphics-scrum-h1423. Hudson has only builds 1414 and 1423
available, so perhaps the issue was introduced before build 1423.

Steps to reproduce the issue:
> cd tests/performace/Surface
> ant
> java -Xmx64m -cp "JFX_HOME/rt/lib/ext/jfxrt.jar;./dist/Surface.jar.jar;../FXBenchmark/dist/FXBenchmark.jar;../../../import/benchmarks-2.1.1/benchmarks-2.1.1.jar"
       jrockit.bm.Main surface.bm.SurfaceBenchmark -i 30 -wt 0 -tr 10 -resolution 150 -movie true