there are a few minor encoder changes, some layout tests will need to be rebaselined.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1eea40afe01fc6ad0c9406bb5a01411ed6549662

commit 1eea40afe01fc6ad0c9406bb5a01411ed6549662
Author: jzern <jzern@chromium.org>
Date: Tue Dec 20 02:19:14 2016

libwebp-0.5.2-rc2

bug fixes, minor encoder updates

BUG= 675306 

Review-Url: https://codereview.chromium.org/2584033003
Cr-Commit-Position: refs/heads/master@{#439671}

[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/WebKit/LayoutTests/platform/linux/virtual/gpu/fast/canvas/canvas-toDataURL-webp-expected.png
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/WebKit/LayoutTests/platform/mac/fast/canvas/canvas-toDataURL-webp-expected.png
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/WebKit/LayoutTests/platform/mac/virtual/display_list_2d_canvas/fast/canvas/canvas-toDataURL-webp-expected.png
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/WebKit/LayoutTests/platform/mac/virtual/gpu/fast/canvas/canvas-toDataURL-webp-expected.png
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/WebKit/LayoutTests/platform/win/fast/canvas/canvas-toDataURL-webp-expected.png
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/WebKit/LayoutTests/platform/win/virtual/display_list_2d_canvas/fast/canvas/canvas-toDataURL-webp-expected.png
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/WebKit/LayoutTests/platform/win/virtual/gpu/fast/canvas/canvas-toDataURL-webp-expected.png
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/README.chromium
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/dec/alpha.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/dec/vp8i.h
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/demux/anim_decode.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/demux/demux.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/dsp/dec.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/dsp/enc.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/dsp/rescaler.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/analysis.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/cost.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/cost.h
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/frame.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/histogram.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/picture.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/picture_csp.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/picture_psnr.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/quant.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/token.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/vp8enci.h
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/enc/vp8l.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/utils/rescaler.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/utils/utils.c
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/utils/utils.h
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/webp/decode.h
[modify] https://crrev.com/1eea40afe01fc6ad0c9406bb5a01411ed6549662/third_party/libwebp/webp/encode.h