67946 Migrate Scaffold SnackBars in the framework to ScaffoldMessenger (a: tests, cla: yes, d: api docs, d: examples, documentation, f: material design, framework, team, waiting for tree to go green)

67971 [flutter_tools] attempt to stabilize hot restart benchmark the old fashioned way (cla: yes, team, tool)

67974 remove missing argument (cla: yes, team)

67976 Move processUtils to globals (cla: yes, team, tool, waiting for tree to go green)

68034 [NNBD] Migrate some Widgets tests (a: tests, cla: yes, framework, team, waiting for tree to go green)

68060 [flutter_tool] support –use-application-binary in flutter drive (cla: yes, team, tool)