x11: Reset the window handle after destroying it

x11: Reset the window handle after destroying it

GLSurface::Destroy() could be called from outside the GLSurface
implementation. Since it is also called in NativeViewGLSurfaceGLX's
destructor, calling Destroy() twice will cause a BadWindow error.

BUG=470004
Committed: https://crrev.com/a7927193002ef9c5a79bd74582260acc9f1ef66d
Cr-Commit-Position: refs/heads/master@{#322494}

[dnicoara, 2015-03-26 22:27:30]

dnicoara@chromium.org changed reviewers:
+ piman@chromium.org

[dnicoara, 2015-03-26 22:27:30]

https://codereview.chromium.org/938873002 adds an explicit call to
GLSurface::Destroy() to make sure surfaceless implementations can clean up
before the context is destroyed. That caused the video_decode_accelerator
unittests to fail on X11.

[piman, 2015-03-26 22:48:48]

lgtm

[dnicoara, 2015-03-26 23:07:07]

The CQ bit was checked by dnicoara@chromium.org

[commit-bot: I haz the power, 2015-03-26 23:08:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1034173004/1

[commit-bot: I haz the power, 2015-03-26 23:30:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-26 23:32:05]

Patchset 1 (id:??) landed as
https://crrev.com/a7927193002ef9c5a79bd74582260acc9f1ef66d
Cr-Commit-Position: refs/heads/master@{#322494}