Add extension flag.
Add Validation check to surface query.
Enable extension for vulkan.
Modify AcquireNextImage to ++frame count and tag images
with frame number.
Buffer age is the difference between current frame count
and the tagged frame number on the buffer.
getBuffeAge may need to trigger AcquireNextImage to be current.
Pass through egl extension and query.
Add EGLBufferAgeTest

Test: angle_end2end_test --gtest_filter=EGLBufferAgeTest
Test: angle_deqp_egl_tests
--deqp-case=dEQP-EGL.functional.buffer_age.*

Bug: angleproject:3529
Change-Id: I0cb94be1c3e85d6f33e82a6a1ccdc9731b6a7f23
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2684724
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>