This could happen because we reset the dirty swap interval flag
before we called makeCurrent.

BUG=angle:481

Change-Id: I15750db8908eb379d89b2b20104dac87c1399987
Reviewed-on: https://chromium-review.googlesource.com/178520Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Commit-Queue: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Shannon Woods <shannonwoods@chromium.org>
Reviewed-by: Nicolas Capens <nicolascapens@chromium.org>
Commit-Queue: Nicolas Capens <nicolascapens@chromium.org>
Tested-by: Nicolas Capens <nicolascapens@chromium.org>