Simplify logic of TapGestureRecognizer (flutter#30227)

Refactors the logic of TapGestureRecognizer, making the calling dependency unidirectional between resolve(accept) and checkUp.

Intercept errors thrown by synchronous Completers in image resolution. (

flutter#30139)

change order of gallery demos

change order of studies again

Move spinner `_defaultSlowWarning` message to a new line (flutter#30071)

* write newline before adding slow restart message to spinner
* update existing test

Make timeout durations configurable (flutter#30053)

Include platformViewId in semantics tree for iOS (flutter#29304)

Include the platformViewId of PlatformViews in the semantics tree. The accessibility bridge in the engine can use this id to steal the semantics nodes from the actual platform view and stick them into Flutter's semantics tree.

It is the iOS PlatformView counter part of flutter#28953. It reverts the change in flutter@5b5d6e8 and flutter@03fd797.

flutter#29302

Fix issue with account drawer header arrow rotating when setState is …

…called (flutter#29980)

The UserAccountsDrawerHeader had a bug with the arrow rotating whenever setState was called on its parent. This change makes sure that we check that the state actually changed before allowing the animation to trigger.

Fixes flutter#25801

ensure that fe server is always built with tool (flutter#29768)

Linking Higher & Lower Class Docs (flutter#29758)

* Adding linking between higher and lower level classes in the API Docs. ref:flutter#22859

* Fixed links between classes.