13148 Revert “Enable/tweak web sdk source maps (#13141)” (cla: yes)

13151 Remove incomplete static thread safety annotations. (cla: yes)

13153 Make the Dart isolate constructor private. (cla: yes)

13154 Fix an output file path for the frontend server package_incremental script (cla: yes)

13155 Roll buildroot to pull in static thread safety analysis options. (cla: yes)

13157 Fix type error in SkVertices (cla: yes)

13158 Add templates to generate fuchsia host bundles (cla: yes)

13159 Move surface-based SceneBuilder implementation under surface/ (cla: yes)