Allow browser compositor control over frames pending with surfaceless rendering on freon.

This adds missing plumbing to single_thread_proxy to forward max pending frames from the surface to the compositor, but keeps max pending value the same for the time being. Currently the call to SetMaxSwapsPendingOnImplThread in layer_tree_host_impl.cc gets dropped on the floor for ChromeOS.

Previously, driver implementation of eglSwapBuffers returned before page flip actually happened, allowing the browser compositor to start scheduling the next frame while the front buffer was still shown.

With switch to freon, SwapBuffersACK is sent on page flip, affecting scheduler timing. This enables the browser compositor to queue up a new frame earlier when necessary.

BUG=465599
Committed: https://crrev.com/346f30ca47612c605de5ae38ac892a6b55554198
Cr-Commit-Position: refs/heads/master@{#322148}

[alexst (slow to review), 2015-03-24 14:47:28]

Patchset #1 (id:1) has been deleted

[alexst (slow to review), 2015-03-24 14:50:16]

alexst@chromium.org changed reviewers:
+ brianderson@chromium.org, piman@chromium.org

[brianderson, 2015-03-25 01:03:05]

lgtm

[piman, 2015-03-25 01:39:17]

lgtm

https://codereview.chromium.org/1011823005/diff/20001/content/browser/composi...
File
content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
(right):

https://codereview.chromium.org/1011823005/diff/20001/content/browser/composi...
content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc:33:
capabilities_.max_frames_pending = 1;
nit: that's already done by BrowserCompositorOutputSurface

[alexst (slow to review), 2015-03-25 02:21:30]

The CQ bit was checked by alexst@chromium.org

[alexst (slow to review), 2015-03-25 02:21:30]

The patchset sent to the CQ was uploaded after l-g-t-m from
brianderson@chromium.org, piman@chromium.org
Link to the patchset: https://codereview.chromium.org/1011823005/#ps40001
(title: "nit")

[commit-bot: I haz the power, 2015-03-25 02:23:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1011823005/40001

[commit-bot: I haz the power, 2015-03-25 04:50:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-03-25 04:50:47]

Try jobs failed on following builders:
  linux_chromium_chromeos_ozone_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[alexst (slow to review), 2015-03-25 12:38:39]

The CQ bit was checked by alexst@chromium.org

[alexst (slow to review), 2015-03-25 12:38:45]

The CQ bit was unchecked by alexst@chromium.org

[alexst (slow to review), 2015-03-25 12:39:15]

The CQ bit was checked by alexst@chromium.org

[commit-bot: I haz the power, 2015-03-25 12:39:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1011823005/40001

[commit-bot: I haz the power, 2015-03-25 13:24:15]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2015-03-25 13:24:57]

Patchset 2 (id:??) landed as
https://crrev.com/346f30ca47612c605de5ae38ac892a6b55554198
Cr-Commit-Position: refs/heads/master@{#322148}