Refactor FrameBuffer2 tests, without mocking the jitter estimator
Refactor FrameBuffer2 tests, without mocking the jitter estimator

Bug: webrtc:7408
Change-Id: Ibded415aefebb9b922ec88c8f5f7fb7ff23cf28d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/134467
Commit-Queue: Niels Moller <0057859e47d61d90529d0f66d9ef692cefedb46a@webrtc.org>
Reviewed-by: Philip Eliasson <729b5e2dca9359bca8c81d600ef9d3e554586ac9@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#27805}

TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc