Update VP9EncoderImpl to use EncodedImage::Allocate
Update VP9EncoderImpl to use EncodedImage::Allocate

Bug: webrtc:9378
Change-Id: I009138b4dc50c4ceb8f94fee6a958bbfa4d7e326
Reviewed-on: https://webrtc-review.googlesource.com/c/121771
Reviewed-by: Rasmus Brandt <9545de3a34b925a736ae2b5ee593f3033f743a28@webrtc.org>
Reviewed-by: Philip Eliasson <729b5e2dca9359bca8c81d600ef9d3e554586ac9@webrtc.org>
Commit-Queue: Niels Moller <0057859e47d61d90529d0f66d9ef692cefedb46a@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26593}
ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc