16963 fix shadows and mask filter blurs (cla: yes)

16965 [web] Fixes IE11 crash due to missing canvas ellipse support and font polyfill failure (cla: yes)

16966 Roll src/third_party/skia db20afc1bf3c..012f8497802e (6 commits) (cla: yes, waiting for tree to go green)

16969 Roll fuchsia/sdk/core/mac-amd64 from 6eF38… to J6ct_… (cla: yes, waiting for tree to go green)

16970 Roll fuchsia/sdk/core/linux-amd64 from cXgMr… to cTw2C… (cla: yes, waiting for tree to go green)