Change FrameBuffer::CombineAndDeleteFrames to allocate a new buffer
Change FrameBuffer::CombineAndDeleteFrames to allocate a new buffer

Modifying buffers passed in to the frame buffer breaks sharing. This
cl is also a preparation for deleting
VCMEncodedFrame::VerifyAndAllocate and EncodedImage::Allocate.

Bug: None
Change-Id: I4e14bc4708bbcbcd91af2d4b764cb9b8271ec090
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/154569
Reviewed-by: Ilya Nikolaevskiy <76788ac3efd229e9d156135d9ceb7fef65c45da4@webrtc.org>
Reviewed-by: Philip Eliasson <729b5e2dca9359bca8c81d600ef9d3e554586ac9@webrtc.org>
Commit-Queue: Niels Moller <0057859e47d61d90529d0f66d9ef692cefedb46a@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#29336}

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