Add API to set sleep time before close.

[philburk]

Add: AudioStream::setDelayBeforeCloseMillis(delay)

This can be used to avoid use-after-free bugs
cause by callbacks running when close is called.

Fixes #1500

[robertwu1]

Can run some tests before/after the changes and verify that the timeout increased a lot if you call setDelayBeforeCloseMillis() on a stream? This might be messy to add as a unit test but a quick sanity check before submitting would be good.

[philburk]

Can run some tests before/after the changes and verify that the timeout increased a lot if you call

"timeout"? Are you suggesting that we measure the time it takes to close a stream and assert that the time increases when we call setDelayBeforeCloseMillis() with a higher value?

[robertwu1]

Can run some tests before/after the changes and verify that the timeout increased a lot if you call

"timeout"? Are you suggesting that we measure the time it takes to close a stream and assert that the time increases when we call setDelayBeforeCloseMillis() with a higher value?

This test works if we set setDelayBeforeCloseMillis() to a ridiculous number like 1000ms. Otherwise, the test may be too noisy.

Alternatively, you can simply change testReturnStop.cpp locally to call setDelayBeforeCloseMillis() as a sanity check.

[philburk]

I added a test that detects the increase in time required to close the stream.
The test was accurate to within a millisecond but I use a bigger tolerance.

[robertwu1]

I added a test that detects the increase in time required to close the stream. The test was accurate to within a millisecond but I use a bigger tolerance.

Great! Are you planning to push your test?

[philburk]

Great! Are you planning to push your test?
Oops. I pushed the wrong branch.
Test now uploaded.

[robertwu1]

Should we make this uint32_t?

[philburk]

The Google C++ style guide says:

You should not use the unsigned integer types such as uint32_t, unless there is a valid reason
such as representing a bit pattern rather than a number, or you need defined overflow
modulo 2^N. In particular, do not use unsigned types to say a number will never be negative.
Instead, use assertions for this.

[robertwu1]

Left some minor comments. Feel free to submit either without addressing my comments or after addressing my comments.