When we move a BufferHelper to the mInFlightBuffers list don't try to unmap it there, instead do that when it gets added to mBufferFreeList This removes 0.75% CPU overhead from a Manhattan30 offscreen run Bug: angleproject:5689 Change-Id: I01a52cdf4803fb8364140b01bedbd3d0e6cc61fd Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2723492 Commit-Queue: Mohan Maiya <m.maiya@samsung.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>
