Change-Id: I7a5230852cb24ce22bfe85ea2608cdb4619b5200

Adds some high-level hooks for profile 2 before further
progress on the implementation.

According to the definitiion in this patch:
1. Profile 2 only supports 10 or 12 bit color but not 8
2. Profile 2 supports all color sampling modes: 444, 422 and 420,
and alpha plane.
3. Profile 3 is currently undefined.

Please consider the definition carefully and suggest modifications
to the definition as needed.

Change-Id: I5b284fc679e54ac5aee171af72fa7994cfd28995

Change-Id: Ib3b3864a6018c62ac1ea18e30795af74464596cd

Change-Id: Ie5723690f7c0bfa29a7ccef5da0c6c6326600ee6

There was a bug with the decoder that if you started the decoder
with more threads than the first frame had tile columns. Afterwards
tried to decode a frame with more tile columns than the first frame,
the decoder would hang. E.g. run vpxdec --threads=4. The first frame
had two tile columns, then the next key frame had 4 tile columns, the
decoder would hang. If you started with 4 tiles and switched to 2
tiles the decoder would be fine. The issue is that the worker the thread
loop is using is stale.

I added a test vector "vp90-2-14-resize-848x480-1280x720.webm" that
exhibited the bug.

Change-Id: I7bdd47241a52ac0fe1c693a609bc779257e94229

Change-Id: If8044d9c71afe02ed1e6c94487344e143bdfcd74

Change-Id: Ieb9b455b8aaef9884391021b7f640ef24c554687

Change-Id: I512f2a287dd8765879a2d1144e2f028dc65f71ff

Change-Id: I0816ec12ec0a6f21d0f25f10c214b5fd327afc6c

Change-Id: I9c5f7edc2d5d1ec5aee396b87bdfc99ee21c435a

Copy up to a certain bsize, otherwise set to a fixed bsize.
This helsp to reduce artifact near moving boundary caused by full partition
copy without checking motion of super-block.
This artifact can occur at speeds 3,4 in real-time mode.
Issue: https://code.google.com/p/webm/issues/detail?id=738.

Change-Id: I05812521fd38816a467f72eb6a951cae4c227931

Change-Id: I5a65d6fdb27516aefda0473ac45b05186cf0913c

Change-Id: Iab3effc39064f265426c82b455ef38d37dcce5a8

Commit introduced the leak: "Removing XMA legacy from VP9 code."
I5e9dfc50b6312848df8c3b8276f6b4d0c7ff9cf9

Change-Id: Ia1f91bb8403bef340de9f089fa78b3fccc3e9917

Change-Id: I7b2b690d2d51d55daa642be4131e5febd78cbe0a

Change-Id: Ic68caec1bcb8a88f443c3e40ce9770eade5bd320

Change-Id: Ib4e31ba74c4b882bd93942ef743f4a189892738d

These functions do nothing about rate control.

Change-Id: I714e80b1c1f4f9aa157a56df705247fce6db138d

ARF overlays now use the same rate correction factor as regular inter
frames, further testing would be needed to see if it makes sense to use
a completely separate rate correction factor for ARF overlays.

$ vpxenc --cpu-used=5  --fps=50/1 --target-bitrate=2000
         parkjoy.y4m -o out.webm
=> Before: 3356 kb/s
=> After: 2271 kb/s

Change-Id: I73e4defa615ba7a8a2bdb845864f4b1721cbbffe