27893 Adds semantics tooltip support (platform-android, cla: yes, waiting for tree to go green, platform-fuchsia, embedder)

27897 fuchsia: Fix thread names + add test (cla: yes, waiting for tree to go green, platform-fuchsia)

27996 GN build rules for tests using Fuchsia SDK Dart libraries and bindings (cla: yes, waiting for tree to go green, platform-fuchsia)

28036 Revert ‘[fuchsia] Make dart_runner work with cfv2 (#27226)’ (cla: yes, platform-fuchsia, needs tests)

28071 Build dart:zircon and dart:zircon_ffi (cla: yes, waiting for tree to go green, platform-fuchsia)