I have found on Wikipedia cache article following sentence " Intel Haswell CPUs with integrated Intel Iris Pro Graphics have 128 MB of eDRAM acting essentially as an L4 cache. The benefits of an L3 cache depend on the application's access patterns."
There is no mention about the L4 cache being shared.
Thanks for your comment. Although I7-4650U is a Haswell CPU, it doesn't has L4 cache. I know many ivybridge CPUs share the last-level cache with GPUs. Not sure about the Haswell notebook CPUs.