Reverts "[Windows] Move to FlutterCompositor for rendering" (#49015)

Reverts #48849
Initiated by: loic-sharma
This change reverts the following previous change:
Original Description:
This migrates the Windows embedder to `FlutterCompositor` so that the engine renders off-screen to a framebuffer instead of directly onto the window's surface. This will allow us to support platform views and multiple views on Windows.

<details>
<summary>Tests...</summary>

* Verify OpenGL compositor's raster time isn't regressed and memory increase is reasonable
* Software compositor's raster time and memory isn't regressed

Test device configurations
* [x] Windows 11 (hardware acceleration enabled/disabled)
* [x] Windows Arm64 (hardware acceleration enabled/disabled)
* [x] Windows 7 (hardware acceleration enabled/disabled, DWM enabled/disabled)

</details>

Addresses flutter/flutter#128904

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

ci/licenses_golden/excluded_files

@@ -367,8 +367,6 @@
 ../../../flutter/shell/platform/windows/client_wrapper/flutter_view_unittests.cc
 ../../../flutter/shell/platform/windows/client_wrapper/plugin_registrar_windows_unittests.cc
 ../../../flutter/shell/platform/windows/client_wrapper/testing
-../../../flutter/shell/platform/windows/compositor_opengl_unittests.cc
-../../../flutter/shell/platform/windows/compositor_software_unittests.cc
 ../../../flutter/shell/platform/windows/cursor_handler_unittests.cc
 ../../../flutter/shell/platform/windows/direct_manipulation_unittests.cc
 ../../../flutter/shell/platform/windows/dpi_utils_unittests.cc

ci/licenses_golden/licenses_flutter

@@ -7117,11 +7117,6 @@ ORIGIN: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/f
 ORIGIN: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flutter_view.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/plugin_registrar_windows.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/windows/compositor.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/windows/compositor_opengl.cc + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/windows/compositor_opengl.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/windows/compositor_software.cc + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/windows/compositor_software.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/windows/cursor_handler.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/windows/cursor_handler.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/windows/direct_manipulation.cc + ../../../flutter/LICENSE
@@ -9956,11 +9951,6 @@ FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flu
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flutter_view.h
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/plugin_registrar_windows.h
-FILE: ../../../flutter/shell/platform/windows/compositor.h
-FILE: ../../../flutter/shell/platform/windows/compositor_opengl.cc
-FILE: ../../../flutter/shell/platform/windows/compositor_opengl.h
-FILE: ../../../flutter/shell/platform/windows/compositor_software.cc
-FILE: ../../../flutter/shell/platform/windows/compositor_software.h
 FILE: ../../../flutter/shell/platform/windows/cursor_handler.cc
 FILE: ../../../flutter/shell/platform/windows/cursor_handler.h
 FILE: ../../../flutter/shell/platform/windows/direct_manipulation.cc

impeller/renderer/backend/gles/description_gles.cc

@@ -156,10 +156,6 @@ std::string DescriptionGLES::GetString() const {
   return stream.str();
 }
 
-Version DescriptionGLES::GetGlVersion() const {
-  return gl_version_;
-}
-
 bool DescriptionGLES::IsES() const {
   return is_es_;
 }

impeller/renderer/backend/gles/description_gles.h

@@ -27,8 +27,6 @@ class DescriptionGLES {
 
   std::string GetString() const;
 
-  Version GetGlVersion() const;
-
   bool HasExtension(const std::string& ext) const;
 
   /// @brief      Returns whether GLES includes the debug extension.

shell/platform/linux/fl_backing_store_provider.cc

@@ -82,8 +82,7 @@ uint32_t fl_backing_store_provider_get_gl_format(FlBackingStoreProvider* self) {
   // In Linux kN32_SkColorType is assumed to be kBGRA_8888_SkColorType.
   // So we must choose a valid gl format to be compatible with surface format
   // BGRA8.
-  // Following logics are copied from Skia GrGLCaps.cpp:
-  // https://github.com/google/skia/blob/4738ed711e03212aceec3cd502a4adb545f38e63/src/gpu/ganesh/gl/GrGLCaps.cpp#L1963-L2116
+  // Following logics are copied from Skia GrGLCaps.cpp.
 
   if (epoxy_is_desktop_gl()) {
     // For OpenGL.

shell/platform/windows/BUILD.gn

@@ -42,11 +42,6 @@ source_set("flutter_windows_source") {
     "accessibility_bridge_windows.h",
     "angle_surface_manager.cc",
     "angle_surface_manager.h",
-    "compositor.h",
-    "compositor_opengl.cc",
-    "compositor_opengl.h",
-    "compositor_software.cc",
-    "compositor_software.h",
     "cursor_handler.cc",
     "cursor_handler.h",
     "direct_manipulation.cc",
@@ -139,7 +134,6 @@ source_set("flutter_windows_source") {
   deps = [
     ":flutter_windows_headers",
     "//flutter/fml:fml",
-    "//flutter/impeller/renderer/backend/gles",
     "//flutter/shell/platform/common:common_cpp",
     "//flutter/shell/platform/common:common_cpp_input",
     "//flutter/shell/platform/common:common_cpp_switches",
@@ -181,8 +175,6 @@ executable("flutter_windows_unittests") {
   # Common Windows test sources.
   sources = [
     "accessibility_bridge_windows_unittests.cc",
-    "compositor_opengl_unittests.cc",
-    "compositor_software_unittests.cc",
     "cursor_handler_unittests.cc",
     "direct_manipulation_unittests.cc",
     "dpi_utils_unittests.cc",
@@ -243,7 +235,6 @@ executable("flutter_windows_unittests") {
     ":flutter_windows_fixtures",
     ":flutter_windows_headers",
     ":flutter_windows_source",
-    "//flutter/impeller/renderer/backend/gles",
     "//flutter/shell/platform/common:common_cpp",
     "//flutter/shell/platform/common/client_wrapper:client_wrapper",
     "//flutter/shell/platform/embedder:embedder_as_internal_library",