CHOP-753: Introduce a sliding window of framerate samples. The trouble with remembering the slowest-ever framerate is that framerate drops dramatically on login, then typically bounces back to something reasonable during the session. So the session-normal framerate has to drop pretty dramatically before it falls below the original login framerate. To address this, only remember the last ~10 minutes of framerates, and log memory stats every time a new framerate is slower than the previous 10 minutes.
CHOP-753: Introduce a sliding window of framerate samples.
The trouble with remembering the slowest-ever framerate is that framerate
drops dramatically on login, then typically bounces back to something
reasonable during the session. So the session-normal framerate has to drop
pretty dramatically before it falls below the original login framerate. To
address this, only remember the last ~10 minutes of framerates, and log memory
stats every time a new framerate is slower than the previous 10 minutes.

gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm