This reverts commit c2879cae2e.
Additionally, we fix https://github.com/flutter/flutter/issues/40863 by adding a secondary VSYNC callback.
Unit tests are updated to provide VSYNC mocking and check the fix of https://github.com/flutter/flutter/issues/40863.
The root cause of having https://github.com/flutter/flutter/issues/40863 is the false assumption that each input event must trigger a new frame. That was true in the framework PR https://github.com/flutter/flutter/pull/36616 because the input events there are all scrolling move events. When the PR was ported to the engine, we can no longer distinguish different types of events, and tap events may no longer trigger a new frame.
Therefore, this PR directly hooks into the `VsyncWaiter` and uses its (newly added) secondary callback to dispatch the pending input event.
Additionally, we now use the engine directly as a delegate instead of storing potentially dead runtime_controller.
Unit tests have been updated to include an engine restart check which would fail before the fix.
This fixes https://github.com/flutter/flutter/issues/40303
Some components in the Flutter engine were derived from the forked blink codebase. While the forked components have either been removed or rewritten, the use of the blink namespace has mostly (and inconsistently) remained. This renames the blink namesapce to flutter for consistency. There are no functional changes in this patch.
When these delegate methods were initially added, it was expected that a single
shell would be able to own mutliple platform views, engines and animators. This
plan was abandoned in favor of creating multiple shells with their own platform
views, engines, etc.. The arguments were meant to ease the disambiguate the
instances of the variaous objects managed by the shell. This is no longer
necessary.
* Flush all embedded Android view on hot restart.
Adds an OnEngineRestarted method to PlatformView, this is currently only
implemented for Android where we need to use it for embedded views.
* review comments followup
* rename to OnPreEngineRestart, call before Clone