Fix failure to recover from GPU hang.

Fix failure to recover from device hang.

Sometimes IDirect3DDevice9Ex::CheckDeviceState returns S_PRESENT_MODE_CHANGED when the GPU has hung. It's not consistent, maybe one time out of two when I hang the GPU while running WebGL Aquarium.

This unfortunately means that changes to display mode will cause ANGLE to report context lost. Other ideas appreciated.
Committed: https://code.google.com/p/angleproject/source/detail?r=1829

[apatrick1, 2013-02-15 00:05:19]

Please take a look.

Al

[apatrick1, 2013-02-15 20:28:01]

I did some more testing. Apparently changing the display mode does _not_ cause
CheckDeviceState to return S_PRESENT_MODE_CHANGE. The only way I've been able to
trigger it is by hanging the GPU.

I should have mentioned. This is how I've been making the GPU hang:

https://www.khronos.org/registry/webgl/conformance-suites/1.0.0/extra/lots-of...

Repro is to go there with Firefox while running the WebGL Aquarium in Chrome.

[shannon.woods_transgaming.com, 2013-02-19 22:58:31]

LGTM

[nicolas, 2013-02-19 23:47:57]

It looks like this could occur when the driver thinks the display mode has
changed:
http://msdn.microsoft.com/en-us/library/windows/desktop/bb219624(v=vs.85).aspx I
guess a lost device could easily lose track of such parameters. According to
this MSDN page, Reset() should be called to stop returning this result code, so
we can indeed treat it the same as a lost device regardless of whether the
device is truly lost or it has fallen back to some emulation mode.

LGTM