Fixes https://github.com/flutter/flutter/issues/21228

This reverts commit d0389701 and updates the tonic SHA.

Reverts flutter/engine#6015

This is causing the Windows bots to fail.

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.

This change adds a delay before Animator::BeginFrame calls its
delegate's OnAnimatorNotifyIdle.  This is because under certain
workloads, such as our parent view resizing us, which is communicated
via viewport change events, we won't have a frame scheduled yet in the
animator, despite the fact that we will go on to schedule a frame once
the viewport event arrives.

In Fuchsia's resizing performance test, on our reference high end x86-64
hardware, the previous logic was resulting in a ~45ms garbage collection
right after the first frame of an animation.

* 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

Don't emit a "VSYNC" event when running on Fuchsia, as traces on Fuchsia
are typically recorded across the whole system, causing the events to
collide with each other.

Fixes https://github.com/flutter/flutter/issues/19571

Needed by code to support Scenic's new API for views.

Thanks Jason for the speedy review

Fixes https://github.com/flutter/flutter/issues/19159

Reverts flutter/engine#5740

Do not make an extra submit callback during SurfaceFrame destruction if the frame was already submitted (#5669)

Part of fixing https://bugs.chromium.org/p/skia/issues/detail?id=7741

Required by the Fuchsia embedder

Toward no-copy loading of kernel.

Previously the engine would load all embedded fonts listed in the app's
font manifest during startup.  This change creates a Skia font manager that
is backed by the engine's AssetManager and can load embedded font assets
on demand.

* Reland "Added IsolateNameServer functionality (#5410)"

This reverts commit c3976b3c.

* Fixed issue with isolate_name_server_test which caused test to timeout

* Disabled thread_annotations on Android as they aren't supported in the
NDK headers for std::mutex. Readded thread annotations to
IsolateNameServer.

This reverts commit 61a2d129.

* Added IsolateNameServer functionality, which allows for the association
of string names with isolate SendPort ids that can be used to establish
inter-isolate communications.

Broke runtime_unittests, which are still running directly from source.

This reverts commit 0ea93c3a.

Eliminates support for running directly from sources or script snapshots. In
debug mode, we run from a kernel snapshot; in profile and release modes, we
link in AOT-compiled code.

Renames --dart-non-checked-mode to --disable-dart-asserts since checked mode
does not make sense in Dart 2.

Adds --dynamic and --interpreter flags to
tools/gn. These flags result in engines with
properties as follows:

--dynamic:
- JIT targeting native code on Android and
  DBC on iOS

--interpreter
- Target DBC even if running on Android.

For example:

gn --android --dynamic --interpreter --runtime-mode release

Will generate an engine:
- Without Dart asserts
- Without Observatory
- With JIT compililation to DBC

into out/android_dynamic_release_dbc

The Fuchsia embedder wants to specify the application name in the field for the advisory URI. This allows embedders to specify whatever they want.