Migrate engine to use multi-window API

ci/licenses_golden/licenses_flutter

@@ -362,10 +362,12 @@ FILE: ../../../flutter/lib/ui/painting/single_frame_codec.h
 FILE: ../../../flutter/lib/ui/painting/vertices.cc
 FILE: ../../../flutter/lib/ui/painting/vertices.h
 FILE: ../../../flutter/lib/ui/painting/vertices_unittests.cc
+FILE: ../../../flutter/lib/ui/platform_dispatcher.dart
 FILE: ../../../flutter/lib/ui/plugins.dart
 FILE: ../../../flutter/lib/ui/plugins/callback_cache.cc
 FILE: ../../../flutter/lib/ui/plugins/callback_cache.h
 FILE: ../../../flutter/lib/ui/pointer.dart
+FILE: ../../../flutter/lib/ui/screen.dart
 FILE: ../../../flutter/lib/ui/semantics.dart
 FILE: ../../../flutter/lib/ui/semantics/custom_accessibility_action.cc
 FILE: ../../../flutter/lib/ui/semantics/custom_accessibility_action.h
@@ -392,6 +394,9 @@ FILE: ../../../flutter/lib/ui/ui_benchmarks.cc
 FILE: ../../../flutter/lib/ui/ui_dart_state.cc
 FILE: ../../../flutter/lib/ui/ui_dart_state.h
 FILE: ../../../flutter/lib/ui/window.dart
+FILE: ../../../flutter/lib/ui/window/platform_configuration.cc
+FILE: ../../../flutter/lib/ui/window/platform_configuration.h
+FILE: ../../../flutter/lib/ui/window/platform_configuration_unittests.cc
 FILE: ../../../flutter/lib/ui/window/platform_message.cc
 FILE: ../../../flutter/lib/ui/window/platform_message.h
 FILE: ../../../flutter/lib/ui/window/platform_message_response.cc
@@ -405,6 +410,10 @@ FILE: ../../../flutter/lib/ui/window/pointer_data_packet.h
 FILE: ../../../flutter/lib/ui/window/pointer_data_packet_converter.cc
 FILE: ../../../flutter/lib/ui/window/pointer_data_packet_converter.h
 FILE: ../../../flutter/lib/ui/window/pointer_data_packet_converter_unittests.cc
+FILE: ../../../flutter/lib/ui/window/screen.cc
+FILE: ../../../flutter/lib/ui/window/screen.h
+FILE: ../../../flutter/lib/ui/window/screen_metrics.cc
+FILE: ../../../flutter/lib/ui/window/screen_metrics.h
 FILE: ../../../flutter/lib/ui/window/viewport_metrics.cc
 FILE: ../../../flutter/lib/ui/window/viewport_metrics.h
 FILE: ../../../flutter/lib/ui/window/window.cc
@@ -439,6 +448,7 @@ FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/picture_recorder.dar
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/platform_message.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/raster_cache.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/rasterizer.dart
+FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/screen_metrics.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/surface.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/text.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/compositor/util.dart
@@ -457,12 +467,14 @@ FILE: ../../../flutter/lib/web_ui/lib/src/engine/mouse_cursor.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/onscreen_logging.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/path_to_svg.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/picture.dart
+FILE: ../../../flutter/lib/web_ui/lib/src/engine/platform_dispatcher.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/platform_views.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/plugins.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/pointer_binding.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/pointer_converter.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/profiler.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/rrect_renderer.dart
+FILE: ../../../flutter/lib/web_ui/lib/src/engine/screen.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/semantics/accessibility.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/semantics/checkable.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/semantics/image.dart
@@ -529,7 +541,9 @@ FILE: ../../../flutter/lib/web_ui/lib/src/ui/natives.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/ui/painting.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/ui/path.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/ui/path_metrics.dart
+FILE: ../../../flutter/lib/web_ui/lib/src/ui/platform_dispatcher.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/ui/pointer.dart
+FILE: ../../../flutter/lib/web_ui/lib/src/ui/screen.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/ui/semantics.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/ui/test_embedding.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/ui/text.dart

lib/ui/BUILD.gn

@@ -89,6 +89,8 @@ source_set("ui") {
     "text/text_box.h",
     "ui_dart_state.cc",
     "ui_dart_state.h",
+    "window/platform_configuration.cc",
+    "window/platform_configuration.h",
     "window/platform_message.cc",
     "window/platform_message.h",
     "window/platform_message_response.cc",
@@ -101,6 +103,10 @@ source_set("ui") {
     "window/pointer_data_packet.h",
     "window/pointer_data_packet_converter.cc",
     "window/pointer_data_packet_converter.h",
+    "window/screen.cc",
+    "window/screen.h",
+    "window/screen_metrics.cc",
+    "window/screen_metrics.h",
     "window/viewport_metrics.cc",
     "window/viewport_metrics.h",
     "window/window.cc",
@@ -165,6 +171,7 @@ if (current_toolchain == host_toolchain) {
       "painting/image_decoder_test.h",
       "painting/image_decoder_unittests.cc",
       "painting/vertices_unittests.cc",
+      "window/platform_configuration_unittests.cc",
       "window/pointer_data_packet_converter_unittests.cc",
     ]
 

lib/ui/compositing.dart

@@ -10,8 +10,8 @@ part of dart.ui;
 ///
 /// To create a Scene object, use a [SceneBuilder].
 ///
-/// Scene objects can be displayed on the screen using the
-/// [Window.render] method.
+/// Scene objects can be displayed on the screen using the [FlutterView.render]
+/// method.
 @pragma('vm:entry-point')
 class Scene extends NativeFieldWrapperClass2 {
   /// This class is created by the engine, and should not be instantiated
@@ -179,7 +179,7 @@ class PhysicalShapeEngineLayer extends _EngineLayerWrapper {
 
 /// Builds a [Scene] containing the given visuals.
 ///
-/// A [Scene] can then be rendered using [Window.render].
+/// A [Scene] can then be rendered using [FlutterView.render].
 ///
 /// To draw graphical operations onto a [Scene], first create a
 /// [Picture] using a [PictureRecorder] and a [Canvas], and then add
@@ -648,13 +648,13 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
   ///  - 0x08: visualizeEngineStatistics - graph UI thread frame times
   /// Set enabledOptions to 0x0F to enable all the currently defined features.
   ///
-  /// The "UI thread" is the thread that includes all the execution of
-  /// the main Dart isolate (the isolate that can call
-  /// [Window.render]). The UI thread frame time is the total time
-  /// spent executing the [Window.onBeginFrame] callback. The "raster
-  /// thread" is the thread (running on the CPU) that subsequently
-  /// processes the [Scene] provided by the Dart code to turn it into
-  /// GPU commands and send it to the GPU.
+  /// The "UI thread" is the thread that includes all the execution of the main
+  /// Dart isolate (the isolate that can call [FlutterView.render]). The UI
+  /// thread frame time is the total time spent executing the
+  /// [PlatformDispatcher.onBeginFrame] callback. The "raster thread" is the
+  /// thread (running on the CPU) that subsequently processes the [Scene]
+  /// provided by the Dart code to turn it into GPU commands and send it to the
+  /// GPU.
   ///
   /// See also the [PerformanceOverlayOption] enum in the rendering library.
   /// for more details.
@@ -795,7 +795,7 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
   ///
   /// Returns a [Scene] containing the objects that have been added to
   /// this scene builder. The [Scene] can then be displayed on the
-  /// screen with [Window.render].
+  /// screen with [FlutterView.render].
   ///
   /// After calling this function, the scene builder object is invalid and
   /// cannot be used further.

lib/ui/compositing/scene.cc

@@ -8,6 +8,7 @@
 #include "flutter/lib/ui/painting/image.h"
 #include "flutter/lib/ui/painting/picture.h"
 #include "flutter/lib/ui/ui_dart_state.h"
+#include "flutter/lib/ui/window/platform_configuration.h"
 #include "flutter/lib/ui/window/window.h"
 #include "third_party/skia/include/core/SkImageInfo.h"
 #include "third_party/skia/include/core/SkSurface.h"
@@ -41,13 +42,21 @@ Scene::Scene(std::shared_ptr<flutter::Layer> rootLayer,
              uint32_t rasterizerTracingThreshold,
              bool checkerboardRasterCacheImages,
              bool checkerboardOffscreenLayers) {
-  auto viewport_metrics = UIDartState::Current()->window()->viewport_metrics();
+  // Currently only support a single window on a single screen.
+  auto viewport_metrics = UIDartState::Current()
+                              ->platform_configuration()
+                              ->get_window(0)
+                              ->viewport_metrics();
+  auto screen_metrics = UIDartState::Current()
+                            ->platform_configuration()
+                            ->get_screen(0)
+                            ->screen_metrics();
 
   layer_tree_ = std::make_unique<LayerTree>(
       SkISize::Make(viewport_metrics.physical_width,
                     viewport_metrics.physical_height),
       static_cast<float>(viewport_metrics.physical_depth),
-      static_cast<float>(viewport_metrics.device_pixel_ratio));
+      static_cast<float>(screen_metrics.device_pixel_ratio));
   layer_tree_->set_root_layer(std::move(rootLayer));
   layer_tree_->set_rasterizer_tracing_threshold(rasterizerTracingThreshold);
   layer_tree_->set_checkerboard_raster_cache_images(

lib/ui/dart_ui.cc

@@ -28,7 +28,7 @@
 #include "flutter/lib/ui/text/font_collection.h"
 #include "flutter/lib/ui/text/paragraph.h"
 #include "flutter/lib/ui/text/paragraph_builder.h"
-#include "flutter/lib/ui/window/window.h"
+#include "flutter/lib/ui/window/platform_configuration.h"
 #include "third_party/tonic/converter/dart_converter.h"
 #include "third_party/tonic/logging/dart_error.h"
 
@@ -81,7 +81,7 @@ void DartUI::InitForGlobal() {
     SemanticsUpdate::RegisterNatives(g_natives);
     SemanticsUpdateBuilder::RegisterNatives(g_natives);
     Vertices::RegisterNatives(g_natives);
-    Window::RegisterNatives(g_natives);
+    PlatformConfiguration::RegisterNatives(g_natives);
 #if defined(OS_FUCHSIA)
     SceneHost::RegisterNatives(g_natives);
 #endif

lib/ui/dart_ui.gni

@@ -12,9 +12,11 @@ dart_ui_files = [
   "//flutter/lib/ui/isolate_name_server.dart",
   "//flutter/lib/ui/lerp.dart",
   "//flutter/lib/ui/natives.dart",
+  "//flutter/lib/ui/platform_dispatcher.dart",
   "//flutter/lib/ui/painting.dart",
   "//flutter/lib/ui/plugins.dart",
   "//flutter/lib/ui/pointer.dart",
+  "//flutter/lib/ui/screen.dart",
   "//flutter/lib/ui/semantics.dart",
   "//flutter/lib/ui/text.dart",
   "//flutter/lib/ui/ui.dart",