Breaking change: removed facilities for JSON and string messaging from FlutterView/FlutterViewController, leaving only binary messaging there. All other use of flutter communication now goes through FlutterMessageChannel and FlutterMethodChannels. Retained use of String and JSON codecs for now.

Companion flutter PR: flutter/flutter#8837

See https://github.com/flutter/flutter/issues/7561

Flutter channels now also supported on iOS. Use FlutterMessageChannel or FlutterMethodChannel with binary/string/json/standard codecs.

New concepts: FlutterMessageChannel (basic message send/receive superseding existing FlutterView methods), FlutterMethodChannel (method invocation and event streams), pluggable codecs for messages and method calls: unencoded binary, string, json, and 'standard' flutter binary encoding.

Adapt to refactoring of snapshot APIs in the Dart VM.

This was causing exceptions on Jellybean

Fixes https://github.com/flutter/flutter/issues/6586

Fixes https://github.com/flutter/flutter/issues/7226

Add a getter for flutterView in FlutterActivity. This allows fullscreen flutter apps to extend FlutterActivity and do custom stuff with the flutter view. (#3324)

Fixes https://github.com/flutter/flutter/issues/7234

FlutterView's host message processing methods are invoked from native code,
and the JNI wrappers will abort the process if the Java side has an uncaught
exception.

Initialize the InputConnection with the text plugin's most recent state (either incoming or outgoing) (#3283)

Fixes https://github.com/flutter/flutter/issues/7033

I updated the C++ and Dart sides but forgot to update the Java side.

Fixes https://github.com/flutter/flutter/issues/6891

These are implemented on macOS and Fuchsia.

(JSONObject.getString() will return the string "null" for a JSON null value)

Fixes https://github.com/flutter/flutter/issues/6643

Update DartServiceIsolate/FlutterView because VMServiceIO_NotifyServerState
now provides a URI for the observatory

We had a typo in our decoding logic.

Fixes https://github.com/flutter/flutter/issues/6564

We no longer use mojom to transport messages. We still use the Mojo EDK
to spin the event loop, however.

Now we just pass the data directly.

Previously, these signals were sent over Mojo. Now we send them through
platform messages.

Instead, just use JNI and Objective-C directly.

This patch removes the use of the host messages mojom and switch all
message routing over to platform messages.

Clients have been migrated to the TextInputPlugin.

This plugin will eventually replace keyboard.mojom.

All the clients have migrated to platform messages.

This will replace raw_keyboard.mojom.

This patch completes the routing for Java-to-Dart platform messages.

This will eventually replace the clipboard mojom.

This functionality has been replaced by the PlatformPlugin. Also move the
contents of //flutter/services/common to more sensible homes.

To make the default state all zeros.

Fixes https://github.com/flutter/flutter/issues/6236

This method will let us remove the activity service.