fix: improve .gitignore.

.gitignore

@@ -1,5 +1,6 @@
 # Miscellaneous
 *.class
+*.lock
 *.log
 *.pyc
 *.swp
@@ -8,7 +9,6 @@
 .buildlog/
 .history
 .svn/
-migrate_working_dir/
 
 # IntelliJ related
 *.iml
@@ -16,32 +16,121 @@ migrate_working_dir/
 *.iws
 .idea/
 
-# The .vscode folder contains launch configuration and tasks you configure in
-# VS Code which you may wish to be included in version control, so this line
-# is commented out by default.
-#.vscode/
+# Visual Studio Code related
+.classpath
+.project
+.settings/
+
+# Flutter repo-specific
+/bin/cache/
+/bin/mingit/
+/dev/benchmarks/mega_gallery/
+/dev/bots/.recipe_deps
+/dev/bots/android_tools/
+/dev/docs/doc/
+/dev/docs/flutter.docs.zip
+/dev/docs/lib/
+/dev/docs/pubspec.yaml
+/dev/integration_tests/**/xcuserdata
+/dev/integration_tests/**/Pods
+/packages/flutter/coverage/
+version
+
+# packages file containing multi-root paths
+.packages.generated
 
 # Flutter/Dart/Pub related
 **/doc/api/
-**/ios/Flutter/.last_build_id
+**/*.g.dart
 .dart_tool/
 .flutter-plugins
 .flutter-plugins-dependencies
+**/generated_plugin_registrant.dart
 .packages
 .pub-cache/
 .pub/
-/build/
+build/
+flutter_*.png
+linked_*.ds
+unlinked.ds
+unlinked_spec.ds
+
+# Android related
+**/android/**/gradle-wrapper.jar
+**/android/.gradle
+**/android/captures/
+**/android/gradlew
+**/android/gradlew.bat
+**/android/local.properties
+**/android/**/GeneratedPluginRegistrant.java
+**/android/key.properties
+*.jks
+
+# iOS/XCode related
+**/ios/**/*.mode1v3
+**/ios/**/*.mode2v3
+**/ios/**/*.moved-aside
+**/ios/**/*.pbxuser
+**/ios/**/*.perspectivev3
+**/ios/**/*sync/
+**/ios/**/.sconsign.dblite
+**/ios/**/.tags*
+**/ios/**/.vagrant/
+**/ios/**/DerivedData/
+**/ios/**/Icon?
+**/ios/**/Pods/
+**/ios/**/.symlinks/
+**/ios/**/profile
+**/ios/**/xcuserdata
+**/ios/.generated/
+**/ios/Flutter/.last_build_id
+**/ios/Flutter/App.framework
+**/ios/Flutter/Flutter.framework
+**/ios/Flutter/Flutter.podspec
+**/ios/Flutter/Generated.xcconfig
+**/ios/Flutter/app.flx
+**/ios/Flutter/app.zip
+**/ios/Flutter/flutter_assets/
+**/ios/Flutter/flutter_export_environment.sh
+**/ios/ServiceDefinitions.json
+**/ios/Runner/GeneratedPluginRegistrant.*
+
+# macOS related
+**/macos/Flutter/GeneratedPluginRegistrant.swift
+**/macos/Flutter/Flutter-Debug.xcconfig
+**/macos/Flutter/Flutter-Release.xcconfig
+**/macos/Flutter/Flutter-Profile.xcconfig
+
+# Windows related
+**/windows/flutter/ephemeral/
+**/windows/**/*.suo
+**/windows/**/*.user
+**/windows/**/*.userosscache
+**/windows/**/*.sln.docstates
+**/windows/x64/
+**/windows/x86/
+**/windows/**/*.[Cc]ache
+**/windows/**/!*.[Cc]ache/
 
 # Web related
 lib/generated_plugin_registrant.dart
 
+# Coverage
+coverage/
+
 # Symbolication related
 app.*.symbols
 
 # Obfuscation related
 app.*.map.json
 
-# Android Studio will place build artifacts here
-/android/app/debug
-/android/app/profile
-/android/app/release
+# Exceptions to above rules.
+!**/ios/**/default.mode1v3
+!**/ios/**/default.mode2v3
+!**/ios/**/default.pbxuser
+!**/ios/**/default.perspectivev3
+!/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages
+!/dev/ci/**/Gemfile.lock
+
+Firebase related
+.firebase