Add doxygen doc generation. (#131356)

dev/docs/README.md

@@ -14,6 +14,14 @@ This site hosts Flutter's API documentation. Other documentation can be found at
 the following locations:
 
 * [flutter.dev](https://flutter.dev) (main site)
+* [api.flutter.dev](https://api.flutter.dev) (API docs reference site)
+* Engine Embedder API documentation:
+  * [Android Embedder](https://api.flutter.dev/javadoc/index.html)
+  * [iOS Embedder](https://api.flutter.dev/ios-embedder/index.html)
+  * [macOS Embedder](https://api.flutter.dev/macos-embedder/index.html)
+  * [Linux Embedder](https://api.flutter.dev/linux-embedder/index.html)
+  * [Windows Embedder](https://api.flutter.dev/windows-embedder/index.html)
+  * [Web Embedder](https://api.flutter.dev/flutter/dart-ui_web/dart-ui_web-library.html)
 * [Installation](https://flutter.dev/docs/get-started/install)
 * [Codelabs](https://flutter.dev/docs/codelabs)
 * [Contributing to Flutter](https://github.com/flutter/flutter/blob/master/CONTRIBUTING.md)

dev/docs/platform_integration/lib/ios.dart

@@ -2,5 +2,5 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-/// [Flutter platform integration APIs for iOS.](https://api.flutter.dev/objcdoc/)
+/// [Flutter platform integration APIs for iOS.](https://api.flutter.dev/ios-embedder/)
 library iOS;

dev/docs/platform_integration/lib/linux.dart

@@ -0,0 +1,6 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// [Flutter platform integration APIs for Linux.](https://api.flutter.dev/linux-embedder/)
+library Linux;

dev/docs/platform_integration/lib/macos.dart

@@ -0,0 +1,6 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// [Flutter platform integration APIs for macOS.](https://api.flutter.dev/macos-embedder/)
+library macOS;

dev/docs/platform_integration/lib/windows.dart

@@ -0,0 +1,6 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// [Flutter platform integration APIs for Windows.](https://api.flutter.dev/windows-embedder/)
+library Windows;

dev/docs/renderers/lib/impeller.dart

@@ -0,0 +1,6 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// [Flutter APIs for the Impeller renderer.](https://api.flutter.dev/impeller/)
+library Impeller;

dev/docs/renderers/pubspec.yaml

@@ -0,0 +1,4 @@
+name: renderers
+
+environment:
+  sdk: '>=2.19.0-0 <4.0.0'