Alternating scroll gestures would sometimes be ignored because _ScrollGestureRecognizer didn't always reset its _state when the pointer[s] went up.
A Dismissable dismiss triggered by a drag and then a fling could cause the next attempt to drag-dimiss to fail.
Fixed the definition of lerpColor().
This patch just adds them to dart:sky. A future patch will actually use them in
the framework once we've published an updated sky_engine package. Also, add
dartdoc to the classes touched in this patch.
Remove all code relating to shadow trees, insertion points, shadow
boundaries, traversing composed trees, distribution, template
documents, custom elements, registering elements, element registries,
element factories, shadow roots, etc.
Remove the following features from the IDLs and from the binding
generators: CustomElementCallbacks, Reflect*, EventHandler.
Remove the CSS custom pseudo-element concept, since we no longer have
a UA style sheet worth talking about, no longer have shadow trees or
custom elements, no longer use pseudo-elements, and generally
therefore don't use this code at all.