Revert "Implement dirty bits acceleration for VertexArrayGL." Seems to cause an exception in Release, in end2end_tests. BUG=angleproject:1040 This reverts commit 6d51c70ccf63a2c5ec240d960ff1bc179d36c92c. Change-Id: I6548bc68dce07d2d85e40afdb604157e689c1d6c Reviewed-on: https://chromium-review.googlesource.com/293821 Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>