libvpx: Pull from upstream

Current HEAD: 38b6aed8fdf50e701c070e708ff7933cc3a61117

git log from upstream:
209ee12 [spatial svc] Remove vpx_svc_parameters_t and the loop that sets it for each layer
4f5b2b2 [spatial svc]Remove quantizers option. Use max/min quantizers for each layer.
76885de [spatial svc] Use string for quantizers and scale-factors option in the test app
f7023ea Remove unnecessary local variable declaration
eee904c Adaptive mode search scheduling
db71c1b Fix compile warning.
c70cea9 Remove mi_grid_* structures.
f34d728 test/tools_common.sh: Add support for dumping list of tests.
822b516 High bit-depth coefficient coding functions
c768162 build/make/iosbuild.sh: Support extra configure args.
c47e420 build/make/rtcd.pl: Add missing arm64 support.
9d3fb75 rtcd: relocate 'extern "C" {' declaration
06fce6b vp8: Update to the adaptive denoising mode.
4eece0d Add a conditional compilation macro to VP8 unit test.
1328431 FIX: vp9_loopfilter_intrin_sse2.c
a86e6e8 Add unit test for VP9 denoiser.
f780b16 [spatial svc] Use same golden frame for all temporal layers
0d3c3d3 Adds high bitdepth convolve, interpred & scaling
c389b37 Substantial reworking of code for arf and kf groups.
217e3cb Improved mb_lpf_horizontal_edge_w_sse2_16() #2
7d0e4f9 Resolves a few gcc warnings
f265dde vp8: common: postproc: fix signed overflow of statement of (X +c) >= X when '-Werror=strict-overflow' is set.
1220b49 arm: Fix building vp8_mse16x16_neon.c with MSVC
81a8138 Adding high-bitdepth intra prediction functions
175d9df Remove memset of every external frame buffer.
adaec4d Speeding up decode_coeffs().

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TBR=tomfinegan@chromium.org

Review URL: https://codereview.chromium.org/592203002

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/libvpx@292074 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
217 files changed