Vendor media_kit_video 2.0.1 with the X11/EGL fix (hardware rendering on X11 with Flutter >= 3.38)

Flutter >= 3.38 keeps its EGL contexts on the raster thread, so
media_kit's video output found none on the platform thread and fell
back to software rendering (no shaders, ~5 fps) on X11. The patched
output opens Flutter's EGL display itself, steps GDK's GLX context aside
on X11 and releases its own context. Patch from a friend's agent, kept
in third_party/media_kit_video/starsync/. Wayland/NVIDIA still renders
on the GPU (checked); the X11 path was verified on the friend's machine.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

third_party/media_kit_video/windows/utils.cc

@@ -0,0 +1,107 @@
+// This file is a part of media_kit
+// (https://github.com/media-kit/media-kit).
+//
+// Copyright © 2021 & onwards, Hitesh Kumar Saini <saini123hitesh@gmail.com>.
+// All rights reserved.
+// Use of this source code is governed by MIT license that can be found in the
+// LICENSE file.
+
+#include "utils.h"
+
+typedef LONG NTSTATUS, *PNTSTATUS;
+#define STATUS_SUCCESS (0x00000000)
+
+typedef NTSTATUS(WINAPI* RtlGetVersionPtr)(PRTL_OSVERSIONINFOW);
+
+void Utils::EnterNativeFullscreen(HWND window) {
+  if (fullscreen_) {
+    return;
+  }
+  fullscreen_ = true;
+
+  // The primary idea here is to revolve around |WS_OVERLAPPEDWINDOW| &
+  // detect/set fullscreen based on it. In the window procedure, this is
+  // separately handled. If there is no |WS_OVERLAPPEDWINDOW| style on the
+  // window i.e. in fullscreen, then no area is left for |WM_NCHITTEST|,
+  // accordingly client area is also expanded to fill whole monitor using
+  // |WM_NCCALCSIZE|.
+
+  auto style = ::GetWindowLongPtr(window, GWL_STYLE);
+  if (style & WS_OVERLAPPEDWINDOW) {
+    auto monitor = MONITORINFO{};
+    auto placement = WINDOWPLACEMENT{};
+    monitor.cbSize = sizeof(MONITORINFO);
+    placement.length = sizeof(WINDOWPLACEMENT);
+    ::GetWindowPlacement(window, &placement);
+    rect_before_fullscreen_ = RECT{
+        placement.rcNormalPosition.left,
+        placement.rcNormalPosition.top,
+        placement.rcNormalPosition.right,
+        placement.rcNormalPosition.bottom,
+    };
+    ::GetMonitorInfo(::MonitorFromWindow(window, MONITOR_DEFAULTTONEAREST),
+                     &monitor);
+    ::SetWindowLongPtr(window, GWL_STYLE, style & ~WS_OVERLAPPEDWINDOW);
+    ::SetWindowPos(window, HWND_TOP, monitor.rcMonitor.left,
+                   monitor.rcMonitor.top,
+                   monitor.rcMonitor.right - monitor.rcMonitor.left,
+                   monitor.rcMonitor.bottom - monitor.rcMonitor.top,
+                   SWP_NOOWNERZORDER | SWP_FRAMECHANGED);
+  }
+}
+
+void Utils::ExitNativeFullscreen(HWND window) {
+  if (!fullscreen_) {
+    return;
+  }
+  fullscreen_ = false;
+
+  auto style = ::GetWindowLongPtr(window, GWL_STYLE);
+  if (!(style & WS_OVERLAPPEDWINDOW)) {
+    ::SetWindowLongPtr(window, GWL_STYLE, style | WS_OVERLAPPEDWINDOW);
+    if (::IsZoomed(window)) {
+      // Refresh the parent window.
+      ::SetWindowPos(window, nullptr, 0, 0, 0, 0,
+                     SWP_NOACTIVATE | SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER |
+                         SWP_FRAMECHANGED);
+      auto rect = RECT{};
+      ::GetClientRect(window, &rect);
+      auto flutter_view =
+          ::FindWindowEx(window, nullptr, kFlutterViewWindowClassName, nullptr);
+      ::SetWindowPos(flutter_view, nullptr, rect.left, rect.top,
+                     rect.right - rect.left, rect.bottom - rect.top,
+                     SWP_NOACTIVATE | SWP_NOZORDER);
+    } else {
+      ::SetWindowPos(
+          window, nullptr, rect_before_fullscreen_.left,
+          rect_before_fullscreen_.top,
+          rect_before_fullscreen_.right - rect_before_fullscreen_.left,
+          rect_before_fullscreen_.bottom - rect_before_fullscreen_.top,
+          SWP_NOACTIVATE | SWP_NOZORDER);
+    }
+  }
+}
+
+RTL_OSVERSIONINFOW Utils::GetWindowsVersion() {
+  HMODULE handle = ::LoadLibraryW(L"ntdll.dll");
+  RTL_OSVERSIONINFOW rtl_os_version_info = {0};
+  rtl_os_version_info.dwBuildNumber = 0;
+  rtl_os_version_info.dwOSVersionInfoSize = sizeof(rtl_os_version_info);
+  if (handle) {
+    RtlGetVersionPtr rtl_get_version_ptr = reinterpret_cast<RtlGetVersionPtr>(
+        ::GetProcAddress(handle, "RtlGetVersion"));
+    if (rtl_get_version_ptr != nullptr) {
+      rtl_get_version_ptr(&rtl_os_version_info);
+    }
+    ::FreeLibrary(handle);
+  }
+  return rtl_os_version_info;
+}
+
+bool Utils::IsWindows10RTMOrGreater() {
+  return GetWindowsVersion().dwBuildNumber >= 10240;
+}
+
+bool Utils::fullscreen_ = false;
+
+RECT Utils::rect_before_fullscreen_ = RECT{};