Allocate tile data adaptively to accommodate the frame size increase

If the frame size increases, the tile data buffer needs to be
re-allocated according to the number of tiles existing in current
frame. This patch makes the multi-tile encoding work in spatial
SVC usage case, and partially solved WebM issue 1018.

Change-Id: I1ad6f33058cf5ce6f60ed5024455a709ca80c5ad
2 files changed