There were some implicit casts in the standard codec implementation that
didn't show up on Linux, but do on Windows.

* Change the virtual display size restriction to warning

- Fixes: https://github.com/flutter/flutter/issues/33290

- This is so we don't block usecases where users show the platform
  view partially.

- https://github.com/flutter/flutter/issues/31990 should address this
  issue more broadly.

* Fix error message

* Allow specifying both Dart and non-Dart fixtures in engine unittests.

This fixes numerous issues in the way in which fixtures were managed
in the engine unit-tests.

* Instead of only being able to specify Dart fixtures, unit-tests may specify
  non-Dart fixtures as well. These are simply copied over to the fixtures
  directory known to the unit-test at runtime.
* An issue where numerous Dart files could be given to the kernel snapshotter
  has been addressed. It was anticipated that such a (legal) invocation to the
  kernel snapshotter would produce a snapshot with the contents of all the Dart
  files added to the root library. This is incorrect and the behavior in this
  case is undefined.
* Dart files referenced by the main Dart file are correctly tracked via a
  depfile.
* The snapshotter arguments have been cleaned up to get rid of unused
  arguments (`—strong`) and  the use of the VM product mode argument has been
  corrected to no longer depend on the Flutter product mode.

As another step toward aligning the macOS plugin API with the iOS plugin
API, and with its final form, rename the plugin-related classes from
FLEPlugin* to FlutterPlugin*. This makes the names of the clasess the
same between iOS and macOS. Eventually they should actually merge, with
annotations/ifdefs for platform differences, but for now since the macOS
version uses the same method names and is simply a subset of the iOS
APIs (with one to-be-stabilized method that is macOS-specific) doing the
merge later won't be a breaking change.

Doing this now allows for building out plugin tooling and plugin
implementations on macOS without creating a growing body of code that
will experience a breaking change later.

See:
https://github.com/flutter/flutter/issues/31735
https://github.com/flutter/flutter/issues/32718

Eliminate an unused import, add missing @Override annotations, and
eliminate an unused logger.

In breaking change flutter/engine#4487, a typo was fixed in our Android
APIs correcting RequestPermissionResult to RequestPermissionsResult
(note the 's' on Permissions) for consistency with the Android SDK.

Various tombstone comments were left to help guide developers in the
right direction. These comments were slated for removal in March of
2018; at over a year later, we can probably safely remove them.

BSDiff is no longer used as of flutter/engine#8663. This removes the
unused Java import and sources.

Corects a bnuch of typeos throughout teh engien codebsae. Also makes
a couple minor Commonwealth -> US spelling adjustments for consistency
with the rest of Flutter's codebase.

Made use of `misspell` tool:
https://github.com/client9/misspell

The framework is currently built with a 10.12 deployment target, so the
podspec can be at 10.12 rather than 10.13.

The TODO is left because this is an update to the current reality rather
than a final decision about what should be supported.

Also remove trailing whitespace on some lines

Uses the new embedding API support for device type and buttons to pass
appropriate mouse button events, allowing for right click, middle click,
etc.

Also fixes some edge cases where macOS event delivery violated Flutter
requirements by tracking more data about the mouse event stream and
adjusting the sent events as necessary.

Based on the iOS Flutter.podspec. This will be used for plugin
management via CocoaPods, as on iOS.

Part of https://github.com/flutter/flutter/issues/32718

Rather than hard-coding the type of incoming events to mouse, and
synthesizing a primary button press for kDown/kUp, expose device kind
and buttons in the API.

For backwards compatibility, if the type is not set, the old behavior is
used. If an embedder sets the type to mouse explicitly, however, they
must also set correct button information.

For the touch type, the API abstracts away the framework's internal
expectation that a button is set for touch down/move for simplicity.

Fixes flutter/flutter#32854

This member variable was added to three classes in #7807, but only
initialized to 0 in one of them. Initialize to 0 in the other two.

macOS uses negative values to represent scrolls to the right, while
Flutter expects the opposite, so flip X deltas.

Adds the flutter/platform channel to the macOS shell, and implements
SystemNavigator.pop.

Other methods from this channel will be implement in the future.

macOS part of flutter/flutter#30713

- Makes json_method_codec.cc compatible with the last stable RapidJSON release.
- Allows removing the GTK dependency with a compile flag.
- Fixes a missing break in a switch flagged by some toolchains.

four_gate -> flutter_runner
dt_rush -> dart_runner

Fuchsia is changing zx_clock_get to return a zx_status_t. This change
prepares us for that change.

New Plugin API PR3: Introduces Service, BroadcastReceiver, and ContentProvider awareness, control surfaces, and plugin bindings. (#8962)

Fixes flutter/flutter#32835

This is forward compatible with std::size and similar to how Chromium
removed use of the arraysize macro.

At a quick glance, one could easily think of the "engine_time" as the
GPU thread time and the "frame_time" as the UI thread time because the
GPU thread time is mainly spent on the engine while the UI thread time
is mainly spent on the Dart framework to generate the frame.

But it's actually the other way. The "engine_time" is UI thread time and
the "frame_time" is the GPU thread time.

To avoid the confusion, rename them to "ui_time" and "raster_time"
respectively. I avoided the "gpu_time" because the rasterization may be
purely on a CPU backed software Skia backend.

New Plugin API PR2: Introduces ActivityAware, ActivityControlSurface, and ActivityPluginBinding. (#8943)