vp9_thread: add vp9_worker_execute()

cherry-picked from:
commit 988b70844e03efcfcc075a9bc25d846670494f36
Author: Pascal Massimino <pascal.massimino@gmail.com>
Date:   Fri Aug 2 11:15:16 2013 -0700

    add WebPWorkerExecute() for convenient bypass

    This is mainly for re-using the worker structs without using the
    thread.

    Change-Id: I8e1be29e53874ef425b15c192fb68036b4c0a359

Original source:
 http://git.chromium.org/webm/libwebp.git
 100644 blob c0d318aee628fdf9ba4876451a28aa978f1066b8 src/utils/thread.c
 100644 blob c2b92c9fe353f8e514f78922f3d237204a9cbc66 src/utils/thread.h

Change-Id: I13fe92b1e94062bb99fdeeb7cb0b4b0575d27793
Removing unused struct member mvcount[MV_VALS].

Change-Id: Iaaca88097904b889769901f2bd331f4fff0e5044
Using stride (# of elements) instead of pitch (bytes) in fdct8x8.

Just making fdct consistent with iht/idct/fht functions which all use
stride (# of elements) as input argument.

Change-Id: Ibc944952a192e6c7b2b6a869ec2894c01da82ed1
Make memory alloc in pick_mode_context bsize aware

This commit makes the buffer allocation of zcoeff_blk array in
pick_mode_context block size aware. It calculates the number of
4x4 blocks in the partition and assigns the memory space accordingly.
This process (and the uninitialization) is done once for each encoding
pass. It allows memory copy of smaller buffer when possible.

For football at 600kbps, the runtimes improve by about 1%:
speed 1, 45961ms -> 45472ms
speed 2, 23863ms -> 23598ms

Change-Id: Id2ca24906fa89f46fa5fe742ec4b8efc2a61f877
Added necessary includes

To avoid the dependency on the order of header files included.

Change-Id: Ic142638d75fe95e6aba41b11664bfa15f076f793
Using INTER_MODES constant instead of MB_MODE_COUNT - NEARESTMV.

Change-Id: Ie5ec392904d03fd5485474b33be8408108e9d3c9
Fix d207 intra prediction SSSE3 functions

This patch fixed a bug that caused 32bit PIC build mismatch. The
stack pointer was modified after "GET_GOT". Loading left pointer
from a hard-coded position gave wrong result.

Change-Id: Iea0aec6f917b12a6b3393ffc986bad74510248cc
Removing NUM_ prefix from constant names.

Renames for consistency with other constants:
  NUM_FRAME_TYPES -> FRAME_TYPES
  NUM_PARTITION_CONTEXTS -> PARTITION_CONTEXTS

Change-Id: I3db30acb2868eb0a424237c831087b2e264ec47f
Reduced delta for kf/gf/arf when at maxq.

Delta reduced because of concern about popping on some
very hard clips.

Also allow some frame recode at speed 2 for kf/gf/arf.

Change-Id: Ib47dff42da41aa6eec83b7285fcaaca24abb851e
Modified no memory rate control.

This 2-pass rate control setting allocates bits based
on first pass stats to each kf group, gf group and individual
frame but does not correct the bits left and allocation after
each frame.

In other words it recommends a bit allocation for each frame
but does not try and correct any over or under spend on a
frame over the remainder of the clip. This reduces the accuracy
of rate control in terms of hitting an average bitrate but prevents
problems that may arise because early frames either use to many
or too few bits. This mode is currently more inclined to undershoot
than overshoot (particularly at higher data rates).

Also minor changes to rate of adaption when recode loop is not
enabled.

This mode is currently enabled by default for VBR.
It gives the following % performance gains.

derf +0.467, +1.072
yt 2.962, 2.645
stdhd 1.682, 1.595,
yt-hd 2.3, 2.174

Change-Id: I3c84a9bf8884e5b345698ff0e19187f792c2f3a0
vp9/dec: use loop filter worker for all inline cases

- uses vp9_worker_execute() in non-threaded case
+ removes hook reassignment

Change-Id: I305fd55f2be5cd92367373c929cdb9004066f90f
vp9_decodemv: limit scope of private function params

replace VP9D_COMP usage with the (slightly) more targeted
VP9_COMMON/MACROBLCKD structures.

Change-Id: Ieafac9ad035cba808ed91d3dfd321ba864b58905
vp9_read_mode_info: limit scope of function params

replace VP9D_COMP usage with the (slightly) more targeted
VP9_COMMON/MACROBLCKD structures.

Change-Id: I09f6c4a5b0bcc20222210831b5b4c1582eced300
vp9_decode_tokens: limit scope of function params

replace VP9D_COMP usage with the (slightly) more targeted
VP9_COMMON/MACROBLCKD/struct segmentation structures.

Change-Id: Iabb3616e231417b0e17b7e4b384ea63167a81745
vp9_decodframe: limit scope of private function params

replace VP9D_COMP usage with the (slightly) more targeted
VP9_COMMON/MACROBLCKD structures.

Change-Id: I50d2579238d1a5d51ba5a82379266448ae64b24b
Merge "Added necessary includes"
Merge "Removing unused struct member mvcount[MV_VALS]."
Moving allow_high_precision_mv from MACROBLOCKD to VP9_COMMON.

This value is a global frame-level flag, not a macroblock-level.

Change-Id: Ie8c5790a931150741c2167c00c3e3dd2cf26744d
Merge "Reduced delta for kf/gf/arf when at maxq."
Merge "Modified no memory rate control."