[video_player] Endorse macOS (flutter#5021)

Endorses the macOS implementation of `video_player`, updating the constraint of the existing `video_player_avfoundation` dependency to ensure macOS support is present. Adds macOS support to the example, and adds macOS discussion to the README.

This is the first macOS plugin with multiple integration test files, which turned up a bug in `flutter test`, so this also includes a repo tooling change to work around that bug for now by running each integration test file separately on macOS (as we already have to do with `flutter drive` on web).

Fixes flutter/flutter#41688

Author: stuartmorgan-g

packages/video_player/video_player/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.8.0
+
+* Adds support for macOS.
+
 ## 2.7.2
 
 * Adds `isCompleted` event to `VideoPlayerEvent`.

packages/video_player/video_player/README.md

@@ -6,9 +6,9 @@
 
 A Flutter plugin for iOS, Android and Web for playing back video on a Widget surface.
 
-|             | Android | iOS   | Web   |
-|-------------|---------|-------|-------|
-| **Support** | SDK 16+ | 11.0+ | Any\* |
+|             | Android | iOS   | macOS  | Web   |
+|-------------|---------|-------|--------|-------|
+| **Support** | SDK 16+ | 11.0+ | 10.14+ | Any\* |
 
 ![The example app running in iOS](https://github.com/flutter/packages/blob/main/packages/video_player/video_player/doc/demo_ipod.gif?raw=true)
 
@@ -33,6 +33,12 @@ Android Manifest file, located in `<project root>/android/app/src/main/AndroidMa
 <uses-permission android:name="android.permission.INTERNET"/>
 ```
 
+### macOS
+
+If you are using network-based videos, you will need to [add the
+`com.apple.security.network.client`
+entitlement](https://docs.flutter.dev/platform-integration/macos/building#entitlements-and-the-app-sandbox)
+
 ### Web
 
 > The Web platform does **not** suppport `dart:io`, so avoid using the `VideoPlayerController.file` constructor for the plugin. Using the constructor attempts to create a `VideoPlayerController.file` that will throw an `UnimplementedError`.
@@ -43,7 +49,7 @@ The `VideoPlayerOptions.mixWithOthers` option can't be implemented in web, at le
 
 ## Supported Formats
 
-- On iOS, the backing player is [AVPlayer](https://developer.apple.com/documentation/avfoundation/avplayer).
+- On iOS and macOS, the backing player is [AVPlayer](https://developer.apple.com/documentation/avfoundation/avplayer).
   The supported formats vary depending on the version of iOS, [AVURLAsset](https://developer.apple.com/documentation/avfoundation/avurlasset) class
   has [audiovisualTypes](https://developer.apple.com/documentation/avfoundation/avurlasset/1386800-audiovisualtypes?language=objc) that you can query for supported av formats.
 - On Android, the backing player is [ExoPlayer](https://google.github.io/ExoPlayer/),

packages/video_player/video_player/example/macos/.gitignore

@@ -0,0 +1,7 @@
+# Flutter-related
+**/Flutter/ephemeral/
+**/Pods/
+
+# Xcode-related
+**/dgph
+**/xcuserdata/

packages/video_player/video_player/example/macos/Flutter/Flutter-Debug.xcconfig

@@ -0,0 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
+#include "ephemeral/Flutter-Generated.xcconfig"

packages/video_player/video_player/example/macos/Flutter/Flutter-Release.xcconfig

@@ -0,0 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
+#include "ephemeral/Flutter-Generated.xcconfig"

packages/video_player/video_player/example/macos/Podfile

@@ -0,0 +1,40 @@
+platform :osx, '10.14'
+
+# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
+ENV['COCOAPODS_DISABLE_STATS'] = 'true'
+
+project 'Runner', {
+  'Debug' => :debug,
+  'Profile' => :release,
+  'Release' => :release,
+}
+
+def flutter_root
+  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'ephemeral', 'Flutter-Generated.xcconfig'), __FILE__)
+  unless File.exist?(generated_xcode_build_settings_path)
+    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure \"flutter pub get\" is executed first"
+  end
+
+  File.foreach(generated_xcode_build_settings_path) do |line|
+    matches = line.match(/FLUTTER_ROOT\=(.*)/)
+    return matches[1].strip if matches
+  end
+  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Flutter-Generated.xcconfig, then run \"flutter pub get\""
+end
+
+require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)
+
+flutter_macos_podfile_setup
+
+target 'Runner' do
+  use_frameworks!
+  use_modular_headers!
+
+  flutter_install_all_macos_pods File.dirname(File.realpath(__FILE__))
+end
+
+post_install do |installer|
+  installer.pods_project.targets.each do |target|
+    flutter_additional_macos_build_settings(target)
+  end
+end