Remove begin_frame_source argument from VulkanBrowserCompositorOutputSurface ctor

This removes an unneeded begin_frame_source from VulkanBrowserCompositorOutputSurface ctor.
I've overlooked this in my previous change (https://codereview.chromium.org/2511273002/).
The code wouldn't actually compile with the argument but I guess this
class isn't built by either local build or trybots - that's why this
has been overlooked.

BUG=467617

Review-Url: https://codereview.chromium.org/2557913002
Cr-Commit-Position: refs/heads/master@{#436847}
2 files changed