Prevent repeated VRDisplay.requestPresent calls from spamming the device

Prevent repeated VRDisplay.requestPresent calls from spamming the device

With this patch new requestPresent calls that are made while the first one is
still pending will simply be queued up Blink-side and all resolved at once when
the original request succeeds or fails.

BUG=670441
Review-Url: https://codereview.chromium.org/2550863002
Cr-Commit-Position: refs/heads/master@{#436132}
(cherry picked from commit dd2fff71ca63ff58973e36c6f411a78f04bcc7fb)

Committed: https://chromium.googlesource.com/chromium/src/+/c634718cdaed84e3f68f324f72908be66a2310e3

[bajones, 2016-12-05 17:44:01]

Description was changed from

==========
Prevent repeated VRDisplay.requestPresent calls from spamming the device

With this patch new requestPresent calls that are made while the first one is
still pending will simply be queued up Blink-side and all resolved at once when
the original request succeeds or fails.

BUG=670441

Review-Url: https://codereview.chromium.org/2550863002
Cr-Commit-Position: refs/heads/master@{#436132}
(cherry picked from commit dd2fff71ca63ff58973e36c6f411a78f04bcc7fb)
==========

to

==========
Prevent repeated VRDisplay.requestPresent calls from spamming the device

With this patch new requestPresent calls that are made while the first one is
still pending will simply be queued up Blink-side and all resolved at once when
the original request succeeds or fails.

BUG=670441

Review-Url: https://codereview.chromium.org/2550863002
Cr-Commit-Position: refs/heads/master@{#436132}
(cherry picked from commit dd2fff71ca63ff58973e36c6f411a78f04bcc7fb)

Committed:
https://chromium.googlesource.com/chromium/src/+/c634718cdaed84e3f68f324f7290...
==========

[bajones, 2016-12-05 17:44:02]

Committed patchset #1 (id:1) manually as
c634718cdaed84e3f68f324f72908be66a2310e3.