Expose basic glib ink annotation interface and enable it in the demo

7 jobs for ink_annotations in 5 minutes and 58 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #4793490
build

00:04:52

passed #4793495
build_android

00:00:40

passed #4793491
build_clang_libcpp

00:04:43

passed #4793494
build_clazy

00:04:24

passed #4793493
build_mingw64_fedora

00:03:51

passed #4793492
build_ubuntu_16_04

00:05:56

passed #4793489
clang_format

00:01:09