Revert r1829: Fix failure to recover from GPU hang.

Revert r1829: Fix failure to recover from GPU hang.

It's causing trouble with Aura. Locking the screen seems to generate the display mode change device status and Aura cannot recover.

http://crbug.com/178148
Committed: https://code.google.com/p/angleproject/source/detail?r=1834

[apatrick1, 2013-02-25 23:39:31]

Locking the screen generates S_PRESENT_MODE_CHANGED and Aura isn't robust to
device lost.

[kbr1, 2013-02-25 23:40:55]

Unfortunate, but LGTM if this is needed for an emergency.

[nicolas, 2013-02-26 16:17:18]

We currently report S_PRESENT_MODE_CHANGED as a lost context in our local
dx11proto branch as well (which will be merged into the public repository soon).
Should we revert it there too or can we expect Aura to be reset robust by the
time this branch is merged into the master branch?

[apatrick1, 2013-02-26 19:02:34]

On 2013/02/26 16:17:18, nicolas wrote:
> We currently report S_PRESENT_MODE_CHANGED as a lost context in our local
> dx11proto branch as well (which will be merged into the public repository
soon).
> Should we revert it there too or can we expect Aura to be reset robust by the
> time this branch is merged into the master branch?

Aura should certainly be robust enough to recover from device lost. I don't
think that should be a consideration for ANGLE.

I have to do some more investigation but I think this is the real issue.
Sometimes a GPU hang is reported with S_PRESENT_MODE_CHANGED rather than an
error. But S_PRESENT_MODE_CHANGED doesn't always mean a GPU hang. It is also
reported when the screen is locked. Losing the context is too harsh a thing to
do just because the screen was locked.

I need a way to differentiate between a GPU hang and the screen being locked and
other things that report S_PRESENT_MODE_CHANGED that do not require the device
be reset. Maybe checking whether GetRenderTargetData succeeds would work.