Roll external/skia c341d3829..be84b720c (27 commits)

https://skia.googlesource.com/skia.git/+log/c341d3829..be84b720c

2018-01-25 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll skia/third_party/externals/angle2/ 68981eb56..2e551f6bc (1 commit)
2018-01-25 reed@google.com compose and combine maskfilters
2018-01-25 scroggo@google.com Remove unused field/methods
2018-01-25 fmalita@chromium.org [skottie] Cache the last keyframe
2018-01-25 stani@google.com Revert "Increase depth threshold for SkClipStack::isRRect."
2018-01-24 fmalita@chromium.org [skottie] Animator scrubbing
2018-01-24 benjaminwagner@google.com [bazel] Add third_party to skia_all_hdrs
2018-01-24 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll skia/third_party/externals/angle2/ 01b21b194..68981eb56 (2 commits)
2018-01-24 mtklein@chromium.org Start of cross process SkScalerContext.
2018-01-24 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll skia/third_party/externals/angle2/ 1b1a8640e..01b21b194 (2 commits)
2018-01-24 robertphillips@google.com Misc guarding of enums in ImageFilter CreateProcs
2018-01-24 mtklein@chromium.org Keep SkRasterPipelineSpriteBlitter's src/dst offset math in size_t
2018-01-24 mtklein@chromium.org pass size_t to ptr_and_ix()
2018-01-24 kjlubick@google.com Update Chromecasts
2018-01-24 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll skia/third_party/externals/angle2/ 112a3a8ef..1b1a8640e (1 commit)
2018-01-24 caryclark@skia.org minor imageinfo fixes
2018-01-24 halcanary@google.com SkQP: Stop requiring users to use posix shell
2018-01-24 halcanary@google.com SkQP:  add slack to model
2018-01-24 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll skia/third_party/externals/angle2/ adcf0ae61..112a3a8ef (1 commit)
2018-01-24 robertphillips@google.com Check enum values in SkDisplacementMapEffect's CreateProc
2018-01-24 robertphillips@google.com Add check for bad enum in SkMatrixConvolutionImageFilter's CreateProc
2018-01-24 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll skia/third_party/externals/angle2/ 7e9b13b5b..adcf0ae61 (1 commit)
2018-01-24 fmalita@chromium.org [skottie] Clamp keyframe values
2018-01-24 reed@google.com fix serializing shadowrec
2018-01-24 mtklein@chromium.org allow 4444 sw surfaces
2018-01-24 egdaniel@google.com Add return value to doLazyInstantiation to know if it succeedes.
2018-01-24 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll skia/third_party/externals/angle2/ c081020c7..7e9b13b5b (1 commit)

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Change-Id: I81a07681fa1c2f495287da8d112d157901807d29
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