include <OpenGL/gl.h> instead of <OpenGL/GL.h>

include <OpenGL/gl.h> instead of <OpenGL/GL.h>

actual file names in OpenGL.framework/Headers is gl.h, not GL.h,
so <OpenGL/GL.h> may fail on case-sensitive filesystem.

BUG=521449
Committed: https://crrev.com/c1f30005558972165dc84fc2f0738801e5675d6a
Cr-Commit-Position: refs/heads/master@{#343851}

[ukai, 2015-08-17 04:05:10]

ukai@chromium.org changed reviewers:
+ ccameron@chromium.org

[ukai, 2015-08-18 05:16:38]

ukai@chromium.org changed reviewers:
+ jbauman@chromium.org, kbr@chromium.org

[Ken Russell (switch to Gerrit), 2015-08-18 05:23:49]

lgtm

[ukai, 2015-08-18 07:01:18]

The CQ bit was checked by ukai@chromium.org

[commit-bot: I haz the power, 2015-08-18 07:01:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1288953006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1288953006/1

[commit-bot: I haz the power, 2015-08-18 07:55:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-18 07:56:36]

Patchset 1 (id:??) landed as
https://crrev.com/c1f30005558972165dc84fc2f0738801e5675d6a
Cr-Commit-Position: refs/heads/master@{#343851}