3959 add a –dart-sdk option to the repo analysis command (cla: yes, waiting for tree to go green)

3964 [multiple_web] Adapt web PlatformView widgets to work slotted. (cla: yes, waiting for tree to go green, p: google_maps_flutter, p: url_launcher, p: video_player, platform-web)

3975 [video_player] Update README.md (cla: yes, waiting for tree to go green, p: video_player)

3978 [google_maps_flutter] Add iOS unit and UI tests (cla: yes, waiting for tree to go green, p: google_maps_flutter, platform-ios)

3982 [script/tool] speed up the pub get portion of the analyze command (cla: yes, waiting for tree to go green)