29791 Acquire context reference at the correct time for FlGlArea. (cla: yes, waiting for tree to go green, platform-linux, needs tests)

29792 [web] Fail if Skia Gold is required but unavailable (cla: yes, waiting for tree to go green, platform-web, needs tests)

29793 Revert 29789 revert 29542 freiling view ref (cla: yes, waiting for tree to go green, platform-fuchsia, needs tests)

29795 [Embedder] Send key data through message channel (platform-ios, cla: yes, platform-fuchsia, embedder)

29796 [flutter_releases] Flutter beta 2.8.0-3.2.pre Engine Cherrypicks (cla: yes)