8837 Only cache required frames (cla: yes)

8841 Update buildroot, libjpeg-turbo and googletest to pull in Fuchsia SDK patches. (cla: yes)

8843 Dynamically add certain AppDelegate methods. (cla: yes)

8844 remove unnecessary usage of runtimeType in dart:ui (cla: yes)

8846 Add asserts to semantics.dart (cla: yes)

8848 Preserve safe area (cla: yes)

8849 new lints (cla: yes)

8851 fix assert (cla: yes)

8859 Get prebuilt Dart via CIPD (cla: yes)

8864 Add resize functions to GLFW shell (cla: yes)