[Linux] Add a 'flutter run' console output test (#118279)

* Add Linux support for the UI integration test project

* Add Linux run console test

.ci.yaml

@@ -687,6 +687,46 @@ targets:
       - bin/**
       - .ci.yaml
 
+  - name: Linux run_debug_test_linux
+    recipe: devicelab/devicelab_drone
+    bringup: true
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "clang", "version": "git_revision:5d5aba78dbbee75508f01bcaa69aedb2ab79065a"},
+          {"dependency": "cmake", "version": "version:3.16.1"},
+          {"dependency": "ninja", "version": "version:1.9.0"}
+        ]
+      tags: >
+        ["devicelab", "hostonly", "linux"]
+      task_name: run_debug_test_linux
+    runIf:
+      - dev/**
+      - packages/flutter_tools/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux run_release_test_linux
+    recipe: devicelab/devicelab_drone
+    bringup: true
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "clang", "version": "git_revision:5d5aba78dbbee75508f01bcaa69aedb2ab79065a"},
+          {"dependency": "cmake", "version": "version:3.16.1"},
+          {"dependency": "ninja", "version": "version:1.9.0"}
+        ]
+      tags: >
+        ["devicelab", "hostonly", "linux"]
+      task_name: run_release_test_linux
+    runIf:
+      - dev/**
+      - packages/flutter_tools/**
+      - bin/**
+      - .ci.yaml
+
   - name: Linux skp_generator
     enabled_branches:
       - main

TESTOWNERS

@@ -251,8 +251,10 @@
 /dev/devicelab/bin/tasks/plugin_test_macos.dart @jmagman @flutter/desktop
 /dev/devicelab/bin/tasks/plugin_test.dart @stuartmorgan @flutter/plugin
 /dev/devicelab/bin/tasks/run_debug_test_android.dart @zanderso @flutter/tool
+/dev/devicelab/bin/tasks/run_debug_test_linux.dart @loic-sharma @flutter/tool
 /dev/devicelab/bin/tasks/run_debug_test_macos.dart @cbracken @flutter/tool
 /dev/devicelab/bin/tasks/run_debug_test_windows.dart @loic-sharma @flutter/tool
+/dev/devicelab/bin/tasks/run_release_test_linux.dart @loic-sharma @flutter/tool
 /dev/devicelab/bin/tasks/run_release_test_macos.dart @cbracken @flutter/tool
 /dev/devicelab/bin/tasks/run_release_test_windows.dart @loic-sharma @flutter/tool
 /dev/devicelab/bin/tasks/technical_debt__cost.dart @HansMuller @flutter/framework

dev/devicelab/bin/tasks/run_debug_test_linux.dart

+// 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.
+
+import 'package:flutter_devicelab/framework/devices.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+import 'package:flutter_devicelab/tasks/run_tests.dart';
+
+Future<void> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.linux;
+  await task(createLinuxRunDebugTest());
+}

dev/devicelab/bin/tasks/run_release_test_linux.dart

+// 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.
+
+import 'package:flutter_devicelab/framework/devices.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+import 'package:flutter_devicelab/tasks/run_tests.dart';
+
+Future<void> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.linux;
+  await task(createLinuxRunReleaseTest());
+}

dev/devicelab/lib/framework/devices.dart

@@ -58,6 +58,7 @@ enum DeviceOperatingSystem {
   fake,
   fuchsia,
   ios,
+  linux,
   macos,
   windows,
 }
@@ -79,6 +80,8 @@ abstract class DeviceDiscovery {
         return IosDeviceDiscovery();
       case DeviceOperatingSystem.fuchsia:
         return FuchsiaDeviceDiscovery();
+      case DeviceOperatingSystem.linux:
+        return LinuxDeviceDiscovery();
       case DeviceOperatingSystem.macos:
         return MacosDeviceDiscovery();
       case DeviceOperatingSystem.windows:
@@ -356,6 +359,40 @@ class AndroidDeviceDiscovery implements DeviceDiscovery {
   }
 }
 
+class LinuxDeviceDiscovery implements DeviceDiscovery {
+  factory LinuxDeviceDiscovery() {
+    return _instance ??= LinuxDeviceDiscovery._();
+  }
+
+  LinuxDeviceDiscovery._();
+
+  static LinuxDeviceDiscovery? _instance;
+
+  static const LinuxDevice _device = LinuxDevice();
+
+  @override
+  Future<Map<String, HealthCheckResult>> checkDevices() async {
+    return <String, HealthCheckResult>{};
+  }
+
+  @override
+  Future<void> chooseWorkingDevice() async { }
+
+  @override
+  Future<void> chooseWorkingDeviceById(String deviceId) async { }
+
+  @override
+  Future<List<String>> discoverDevices() async {
+    return <String>['linux'];
+  }
+
+  @override
+  Future<void> performPreflightTasks() async { }
+
+  @override
+  Future<Device> get workingDevice  async => _device;
+}
+
 class MacosDeviceDiscovery implements DeviceDiscovery {
   factory MacosDeviceDiscovery() {
     return _instance ??= MacosDeviceDiscovery._();
@@ -1046,6 +1083,58 @@ class IosDevice extends Device {
   }
 }
 
+class LinuxDevice extends Device {
+  const LinuxDevice();
+
+  @override
+  String get deviceId => 'linux';
+
+  @override
+  Future<Map<String, dynamic>> getMemoryStats(String packageName) async {
+    return <String, dynamic>{};
+  }
+
+  @override
+  Future<void> home() async { }
+
+  @override
+  Future<bool> isAsleep() async {
+    return false;
+  }
+
+  @override
+  Future<bool> isAwake() async {
+    return true;
+  }
+
+  @override
+  Stream<String> get logcat => const Stream<String>.empty();
+
+  @override
+  Future<void> clearLogs() async {}
+
+  @override
+  Future<void> reboot() async { }
+
+  @override
+  Future<void> sendToSleep() async { }
+
+  @override
+  Future<void> stop(String packageName) async { }
+
+  @override
+  Future<void> tap(int x, int y) async { }
+
+  @override
+  Future<void> togglePower() async { }
+
+  @override
+  Future<void> unlock() async { }
+
+  @override
+  Future<void> wakeUp() async { }
+}
+
 class MacosDevice extends Device {
   const MacosDevice();
 

dev/devicelab/lib/tasks/perf_tests.dart

@@ -716,6 +716,7 @@ class StartupTest {
           break;
         case DeviceOperatingSystem.fake:
         case DeviceOperatingSystem.fuchsia:
+        case DeviceOperatingSystem.linux:
           break;
         case DeviceOperatingSystem.ios:
         case DeviceOperatingSystem.macos:
@@ -860,6 +861,7 @@ class DevtoolsStartupTest {
           break;
         case DeviceOperatingSystem.fake:
         case DeviceOperatingSystem.fuchsia:
+        case DeviceOperatingSystem.linux:
         case DeviceOperatingSystem.macos:
         case DeviceOperatingSystem.windows:
           break;
@@ -1571,6 +1573,8 @@ class CompileTest {
         throw Exception('Unsupported option for fake devices');
       case DeviceOperatingSystem.fuchsia:
         throw Exception('Unsupported option for Fuchsia devices');
+      case DeviceOperatingSystem.linux:
+        throw Exception('Unsupported option for Linux devices');
       case DeviceOperatingSystem.windows:
         unawaited(stderr.flush());
         options.insert(0, 'windows');
@@ -1634,6 +1638,8 @@ class CompileTest {
         throw Exception('Unsupported option for fake devices');
       case DeviceOperatingSystem.fuchsia:
         throw Exception('Unsupported option for Fuchsia devices');
+      case DeviceOperatingSystem.linux:
+        throw Exception('Unsupported option for Linux devices');
       case DeviceOperatingSystem.macos:
         unawaited(stderr.flush());
         options.insert(0, 'macos');
@@ -1687,6 +1693,7 @@ class CompileTest {
       case DeviceOperatingSystem.androidArm64:
       case DeviceOperatingSystem.fake:
       case DeviceOperatingSystem.fuchsia:
+      case DeviceOperatingSystem.linux:
       case DeviceOperatingSystem.windows:
         throw Exception('Called ${CompileTest.getSizesFromDarwinApp} with $operatingSystem.');
     }

dev/devicelab/lib/tasks/run_tests.dart

@@ -19,6 +19,22 @@ TaskFunction createAndroidRunReleaseTest() {
   return AndroidRunOutputTest(release: true).call;
 }
 
+TaskFunction createLinuxRunDebugTest() {
+  return DesktopRunOutputTest(
+    '${flutterDirectory.path}/dev/integration_tests/ui',
+    'lib/empty.dart',
+    release: false,
+  ).call;
+}
+
+TaskFunction createLinuxRunReleaseTest() {
+  return DesktopRunOutputTest(
+    '${flutterDirectory.path}/dev/integration_tests/ui',
+    'lib/empty.dart',
+    release: true,
+  ).call;
+}
+
 TaskFunction createMacOSRunDebugTest() {
   return DesktopRunOutputTest(
     // TODO(cbracken): https://github.com/flutter/flutter/issues/87508#issuecomment-1043753201

dev/integration_tests/ui/linux/.gitignore

+flutter/ephemeral

dev/integration_tests/ui/linux/CMakeLists.txt

+# Project-level configuration.
+cmake_minimum_required(VERSION 3.10)
+project(runner LANGUAGES CXX)
+
+# The name of the executable created for the application. Change this to change
+# the on-disk name of your application.
+set(BINARY_NAME "ui")
+# The unique GTK application identifier for this application. See:
+# https://wiki.gnome.org/HowDoI/ChooseApplicationID
+set(APPLICATION_ID "io.flutter.ui")
+
+# Explicitly opt in to modern CMake behaviors to avoid warnings with recent
+# versions of CMake.
+cmake_policy(SET CMP0063 NEW)
+
+# Load bundled libraries from the lib/ directory relative to the binary.
+set(CMAKE_INSTALL_RPATH "$ORIGIN/lib")
+
+# Root filesystem for cross-building.
+if(FLUTTER_TARGET_PLATFORM_SYSROOT)
+  set(CMAKE_SYSROOT ${FLUTTER_TARGET_PLATFORM_SYSROOT})
+  set(CMAKE_FIND_ROOT_PATH ${CMAKE_SYSROOT})
+  set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+  set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
+  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+endif()
+
+# Define build configuration options.
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+  set(CMAKE_BUILD_TYPE "Debug" CACHE
+    STRING "Flutter build mode" FORCE)
+  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS
+    "Debug" "Profile" "Release")
+endif()
+
+# Compilation settings that should be applied to most targets.
+#
+# Be cautious about adding new options here, as plugins use this function by
+# default. In most cases, you should add new options to specific targets instead
+# of modifying this function.
+function(APPLY_STANDARD_SETTINGS TARGET)
+  target_compile_features(${TARGET} PUBLIC cxx_std_14)
+  target_compile_options(${TARGET} PRIVATE -Wall -Werror)
+  target_compile_options(${TARGET} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:-O3>")
+  target_compile_definitions(${TARGET} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:NDEBUG>")
+endfunction()
+
+# Flutter library and tool build rules.
+set(FLUTTER_MANAGED_DIR "${CMAKE_CURRENT_SOURCE_DIR}/flutter")
+add_subdirectory(${FLUTTER_MANAGED_DIR})
+
+# System-level dependencies.
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(GTK REQUIRED IMPORTED_TARGET gtk+-3.0)
+
+add_definitions(-DAPPLICATION_ID="${APPLICATION_ID}")
+
+# Define the application target. To change its name, change BINARY_NAME above,
+# not the value here, or `flutter run` will no longer work.
+#
+# Any new source files that you add to the application should be added here.
+add_executable(${BINARY_NAME}
+  "main.cc"
+  "my_application.cc"
+  "${FLUTTER_MANAGED_DIR}/generated_plugin_registrant.cc"
+)
+
+# Apply the standard set of build settings. This can be removed for applications
+# that need different build settings.
+apply_standard_settings(${BINARY_NAME})
+
+# Add dependency libraries. Add any application-specific dependencies here.
+target_link_libraries(${BINARY_NAME} PRIVATE flutter)
+target_link_libraries(${BINARY_NAME} PRIVATE PkgConfig::GTK)
+
+# Run the Flutter tool portions of the build. This must not be removed.
+add_dependencies(${BINARY_NAME} flutter_assemble)
+
+# Only the install-generated bundle's copy of the executable will launch
+# correctly, since the resources must in the right relative locations. To avoid
+# people trying to run the unbundled copy, put it in a subdirectory instead of
+# the default top-level location.
+set_target_properties(${BINARY_NAME}
+  PROPERTIES
+  RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/intermediates_do_not_run"
+)
+
+# Generated plugin build rules, which manage building the plugins and adding
+# them to the application.
+include(flutter/generated_plugins.cmake)
+
+
+# === Installation ===
+# By default, "installing" just makes a relocatable bundle in the build
+# directory.
+set(BUILD_BUNDLE_DIR "${PROJECT_BINARY_DIR}/bundle")
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+  set(CMAKE_INSTALL_PREFIX "${BUILD_BUNDLE_DIR}" CACHE PATH "..." FORCE)
+endif()
+
+# Start with a clean build bundle directory every time.
+install(CODE "
+  file(REMOVE_RECURSE \"${BUILD_BUNDLE_DIR}/\")
+  " COMPONENT Runtime)
+
+set(INSTALL_BUNDLE_DATA_DIR "${CMAKE_INSTALL_PREFIX}/data")
+set(INSTALL_BUNDLE_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib")
+
+install(TARGETS ${BINARY_NAME} RUNTIME DESTINATION "${CMAKE_INSTALL_PREFIX}"
+  COMPONENT Runtime)
+
+install(FILES "${FLUTTER_ICU_DATA_FILE}" DESTINATION "${INSTALL_BUNDLE_DATA_DIR}"
+  COMPONENT Runtime)
+
+install(FILES "${FLUTTER_LIBRARY}" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+  COMPONENT Runtime)
+
+foreach(bundled_library ${PLUGIN_BUNDLED_LIBRARIES})
+  install(FILES "${bundled_library}"
+    DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+    COMPONENT Runtime)
+endforeach(bundled_library)
+
+# Fully re-copy the assets directory on each build to avoid having stale files
+# from a previous install.
+set(FLUTTER_ASSET_DIR_NAME "flutter_assets")
+install(CODE "
+  file(REMOVE_RECURSE \"${INSTALL_BUNDLE_DATA_DIR}/${FLUTTER_ASSET_DIR_NAME}\")
+  " COMPONENT Runtime)
+install(DIRECTORY "${PROJECT_BUILD_DIR}/${FLUTTER_ASSET_DIR_NAME}"
+  DESTINATION "${INSTALL_BUNDLE_DATA_DIR}" COMPONENT Runtime)
+
+# Install the AOT library on non-Debug builds only.
+if(NOT CMAKE_BUILD_TYPE MATCHES "Debug")
+  install(FILES "${AOT_LIBRARY}" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+    COMPONENT Runtime)
+endif()

dev/integration_tests/ui/linux/flutter/CMakeLists.txt

+# This file controls Flutter-level build steps. It should not be edited.
+cmake_minimum_required(VERSION 3.10)
+
+set(EPHEMERAL_DIR "${CMAKE_CURRENT_SOURCE_DIR}/ephemeral")
+
+# Configuration provided via flutter tool.
+include(${EPHEMERAL_DIR}/generated_config.cmake)
+
+# TODO: Move the rest of this into files in ephemeral. See
+# https://github.com/flutter/flutter/issues/57146.
+
+# Serves the same purpose as list(TRANSFORM ... PREPEND ...),
+# which isn't available in 3.10.
+function(list_prepend LIST_NAME PREFIX)
+    set(NEW_LIST "")
+    foreach(element ${${LIST_NAME}})
+        list(APPEND NEW_LIST "${PREFIX}${element}")
+    endforeach(element)
+    set(${LIST_NAME} "${NEW_LIST}" PARENT_SCOPE)
+endfunction()
+
+# === Flutter Library ===
+# System-level dependencies.
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(GTK REQUIRED IMPORTED_TARGET gtk+-3.0)
+pkg_check_modules(GLIB REQUIRED IMPORTED_TARGET glib-2.0)
+pkg_check_modules(GIO REQUIRED IMPORTED_TARGET gio-2.0)
+
+set(FLUTTER_LIBRARY "${EPHEMERAL_DIR}/libflutter_linux_gtk.so")
+
+# Published to parent scope for install step.
+set(FLUTTER_LIBRARY ${FLUTTER_LIBRARY} PARENT_SCOPE)
+set(FLUTTER_ICU_DATA_FILE "${EPHEMERAL_DIR}/icudtl.dat" PARENT_SCOPE)
+set(PROJECT_BUILD_DIR "${PROJECT_DIR}/build/" PARENT_SCOPE)
+set(AOT_LIBRARY "${PROJECT_DIR}/build/lib/libapp.so" PARENT_SCOPE)
+
+list(APPEND FLUTTER_LIBRARY_HEADERS
+  "fl_basic_message_channel.h"
+  "fl_binary_codec.h"
+  "fl_binary_messenger.h"
+  "fl_dart_project.h"
+  "fl_engine.h"
+  "fl_json_message_codec.h"
+  "fl_json_method_codec.h"
+  "fl_message_codec.h"
+  "fl_method_call.h"
+  "fl_method_channel.h"
+  "fl_method_codec.h"
+  "fl_method_response.h"
+  "fl_plugin_registrar.h"
+  "fl_plugin_registry.h"
+  "fl_standard_message_codec.h"
+  "fl_standard_method_codec.h"
+  "fl_string_codec.h"
+  "fl_value.h"
+  "fl_view.h"
+  "flutter_linux.h"
+)
+list_prepend(FLUTTER_LIBRARY_HEADERS "${EPHEMERAL_DIR}/flutter_linux/")
+add_library(flutter INTERFACE)
+target_include_directories(flutter INTERFACE
+  "${EPHEMERAL_DIR}"
+)
+target_link_libraries(flutter INTERFACE "${FLUTTER_LIBRARY}")
+target_link_libraries(flutter INTERFACE
+  PkgConfig::GTK
+  PkgConfig::GLIB
+  PkgConfig::GIO
+)
+add_dependencies(flutter flutter_assemble)
+
+# === Flutter tool backend ===
+# _phony_ is a non-existent file to force this command to run every time,
+# since currently there's no way to get a full input/output list from the
+# flutter tool.
+add_custom_command(
+  OUTPUT ${FLUTTER_LIBRARY} ${FLUTTER_LIBRARY_HEADERS}
+    ${CMAKE_CURRENT_BINARY_DIR}/_phony_
+  COMMAND ${CMAKE_COMMAND} -E env
+    ${FLUTTER_TOOL_ENVIRONMENT}
+    "${FLUTTER_ROOT}/packages/flutter_tools/bin/tool_backend.sh"
+      ${FLUTTER_TARGET_PLATFORM} ${CMAKE_BUILD_TYPE}
+  VERBATIM
+)
+add_custom_target(flutter_assemble DEPENDS
+  "${FLUTTER_LIBRARY}"
+  ${FLUTTER_LIBRARY_HEADERS}
+)

dev/integration_tests/ui/linux/flutter/generated_plugins.cmake

+#
+# Generated file, do not edit.
+#
+
+list(APPEND FLUTTER_PLUGIN_LIST
+)
+
+list(APPEND FLUTTER_FFI_PLUGIN_LIST
+)
+
+set(PLUGIN_BUNDLED_LIBRARIES)
+
+foreach(plugin ${FLUTTER_PLUGIN_LIST})
+  add_subdirectory(flutter/ephemeral/.plugin_symlinks/${plugin}/linux plugins/${plugin})
+  target_link_libraries(${BINARY_NAME} PRIVATE ${plugin}_plugin)
+  list(APPEND PLUGIN_BUNDLED_LIBRARIES $<TARGET_FILE:${plugin}_plugin>)
+  list(APPEND PLUGIN_BUNDLED_LIBRARIES ${${plugin}_bundled_libraries})
+endforeach(plugin)
+
+foreach(ffi_plugin ${FLUTTER_FFI_PLUGIN_LIST})
+  add_subdirectory(flutter/ephemeral/.plugin_symlinks/${ffi_plugin}/linux plugins/${ffi_plugin})
+  list(APPEND PLUGIN_BUNDLED_LIBRARIES ${${ffi_plugin}_bundled_libraries})
+endforeach(ffi_plugin)

dev/integration_tests/ui/linux/main.cc

+#include "my_application.h"
+
+int main(int argc, char** argv) {
+  g_autoptr(MyApplication) app = my_application_new();
+  return g_application_run(G_APPLICATION(app), argc, argv);
+}

dev/integration_tests/ui/linux/my_application.cc

+#include "my_application.h"
+
+#include <flutter_linux/flutter_linux.h>
+#ifdef GDK_WINDOWING_X11
+#include <gdk/gdkx.h>
+#endif
+
+#include "flutter/generated_plugin_registrant.h"
+
+struct _MyApplication {
+  GtkApplication parent_instance;
+  char** dart_entrypoint_arguments;
+};
+
+G_DEFINE_TYPE(MyApplication, my_application, GTK_TYPE_APPLICATION)
+
+// Implements GApplication::activate.
+static void my_application_activate(GApplication* application) {
+  MyApplication* self = MY_APPLICATION(application);
+  GtkWindow* window =
+      GTK_WINDOW(gtk_application_window_new(GTK_APPLICATION(application)));
+
+  // Use a header bar when running in GNOME as this is the common style used
+  // by applications and is the setup most users will be using (e.g. Ubuntu
+  // desktop).
+  // If running on X and not using GNOME then just use a traditional title bar
+  // in case the window manager does more exotic layout, e.g. tiling.
+  // If running on Wayland assume the header bar will work (may need changing
+  // if future cases occur).
+  gboolean use_header_bar = TRUE;
+#ifdef GDK_WINDOWING_X11
+  GdkScreen* screen = gtk_window_get_screen(window);
+  if (GDK_IS_X11_SCREEN(screen)) {
+    const gchar* wm_name = gdk_x11_screen_get_window_manager_name(screen);
+    if (g_strcmp0(wm_name, "GNOME Shell") != 0) {
+      use_header_bar = FALSE;
+    }
+  }
+#endif
+  if (use_header_bar) {
+    GtkHeaderBar* header_bar = GTK_HEADER_BAR(gtk_header_bar_new());
+    gtk_widget_show(GTK_WIDGET(header_bar));
+    gtk_header_bar_set_title(header_bar, "ui");
+    gtk_header_bar_set_show_close_button(header_bar, TRUE);
+    gtk_window_set_titlebar(window, GTK_WIDGET(header_bar));
+  } else {
+    gtk_window_set_title(window, "ui");
+  }
+
+  gtk_window_set_default_size(window, 1280, 720);
+  gtk_widget_show(GTK_WIDGET(window));
+
+  g_autoptr(FlDartProject) project = fl_dart_project_new();
+  fl_dart_project_set_dart_entrypoint_arguments(project, self->dart_entrypoint_arguments);
+
+  FlView* view = fl_view_new(project);
+  gtk_widget_show(GTK_WIDGET(view));
+  gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(view));
+
+  fl_register_plugins(FL_PLUGIN_REGISTRY(view));
+
+  gtk_widget_grab_focus(GTK_WIDGET(view));
+}
+
+// Implements GApplication::local_command_line.
+static gboolean my_application_local_command_line(GApplication* application, gchar*** arguments, int* exit_status) {
+  MyApplication* self = MY_APPLICATION(application);
+  // Strip out the first argument as it is the binary name.
+  self->dart_entrypoint_arguments = g_strdupv(*arguments + 1);
+
+  g_autoptr(GError) error = nullptr;
+  if (!g_application_register(application, nullptr, &error)) {
+     g_warning("Failed to register: %s", error->message);
+     *exit_status = 1;
+     return TRUE;
+  }
+
+  g_application_activate(application);
+  *exit_status = 0;
+
+  return TRUE;
+}
+
+// Implements GObject::dispose.
+static void my_application_dispose(GObject* object) {
+  MyApplication* self = MY_APPLICATION(object);
+  g_clear_pointer(&self->dart_entrypoint_arguments, g_strfreev);
+  G_OBJECT_CLASS(my_application_parent_class)->dispose(object);
+}
+
+static void my_application_class_init(MyApplicationClass* klass) {
+  G_APPLICATION_CLASS(klass)->activate = my_application_activate;
+  G_APPLICATION_CLASS(klass)->local_command_line = my_application_local_command_line;
+  G_OBJECT_CLASS(klass)->dispose = my_application_dispose;
+}
+
+static void my_application_init(MyApplication* self) {}
+
+MyApplication* my_application_new() {
+  return MY_APPLICATION(g_object_new(my_application_get_type(),
+                                     "application-id", APPLICATION_ID,
+                                     "flags", G_APPLICATION_NON_UNIQUE,
+                                     nullptr));
+}

dev/integration_tests/ui/linux/my_application.h

+// 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.
+
+#ifndef FLUTTER_MY_APPLICATION_H_
+#define FLUTTER_MY_APPLICATION_H_
+
+#include <gtk/gtk.h>
+
+G_DECLARE_FINAL_TYPE(MyApplication, my_application, MY, APPLICATION,
+                     GtkApplication)
+
+/**
+ * my_application_new:
+ *
+ * Creates a new Flutter-based application.
+ *
+ * Returns: a new #MyApplication.
+ */
+MyApplication* my_application_new();
+
+#endif  // FLUTTER_MY_APPLICATION_H_