ozone: Add egltest platform (reland)

ozone: Add egltest platform (reland)

This supports testing rendering using EGL. Creation of the
EGLNativeWindowType is punted to a separate library, which has an
interface defined in eglplatform_shim.h.

TEST=ninja -C out_ozone/Debug aura_builder &&
  content_shell --ozone-platform=egltest --ignore-gpu-blacklist
BUG=none
TBR=spang

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270737

[spang, 2014-05-15 13:33:38]

The CQ bit was checked by spang@chromium.org

[commit-bot: I haz the power, 2014-05-15 13:34:22]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/spang@chromium.org/282193003/1

[spang, 2014-05-15 15:10:34]

The CQ bit was unchecked by spang@chromium.org

[spang, 2014-05-15 15:50:37]

The CQ bit was checked by spang@chromium.org

[commit-bot: I haz the power, 2014-05-15 15:52:47]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/spang@chromium.org/282193003/20001

[commit-bot: I haz the power, 2014-05-15 17:35:24]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  ios_dbg_simulator on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_dbg_simulator/bui...)

[commit-bot: I haz the power, 2014-05-15 18:09:11]

Change committed as 270737