Package CEF as NuGet package, does not need to be manually downloaded anymore.

Robust.Client.WebView/Cef/Program.cs

@@ -1,4 +1,7 @@
 using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using Robust.Shared.ContentPack;
 using Xilium.CefGlue;
 
 namespace Robust.Client.WebView.Cef
@@ -16,7 +19,20 @@ namespace Robust.Client.WebView.Cef
                 Array.Copy(args, 0, argv, 1, args.Length);
                 argv[0] = "-";
             }
+/* 
+            if (OperatingSystem.IsLinux())
+            {
+                // Chromium tries to load libEGL.so and libGLESv2.so relative to the process executable on Linux.
+                // (Compared to Windows where it is relative to Chromium's *module*)
+                // There is a TODO "is this correct?" in the Chromium code for this.
+                // Great.
+                
+                //CopyDllToExecutableDir("libEGL.so");
+                //CopyDllToExecutableDir("libGLESv2.so");
 
+                // System.Threading.Thread.Sleep(200000);
+            }
+ */
             var mainArgs = new CefMainArgs(argv);
 
             // This will block executing until the subprocess is shut down.
@@ -29,5 +45,44 @@ namespace Robust.Client.WebView.Cef
 
             return code;
         }
+
+/*         private static void CopyDllToExecutableDir(string dllName)
+        {
+            var executableDir = PathHelpers.GetExecutableDirectory();
+            var targetPath = Path.Combine(executableDir, dllName);
+            if (File.Exists(targetPath))
+                return;
+
+            // Find source file.
+            string? srcFile = null;
+            foreach (var searchDir in WebViewManagerCef.NativeDllSearchDirectories())
+            {
+                var searchPath = Path.Combine(searchDir, dllName);
+                if (File.Exists(searchPath))
+                {
+                    srcFile = searchPath;
+                    break;
+                }
+            }
+
+            if (srcFile == null)
+                return;
+
+            for (var i = 0; i < 5; i++)
+            {
+                try
+                {
+                    if (File.Exists(targetPath))
+                        return;
+
+                    File.Copy(srcFile, targetPath);
+                    return;
+                }
+                catch 
+                {
+                    // Catching race condition lock errors and stuff I guess.
+                }
+            }
+        } */
     }
 }

Robust.Client.WebView/Cef/RobustCefApp.cs

@@ -1,3 +1,4 @@
+using System;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Xilium.CefGlue;
@@ -23,6 +24,12 @@ namespace Robust.Client.WebView.Cef
         {
             // Disable zygote on Linux.
             commandLine.AppendSwitch("--no-zygote");
+            
+            // Work around https://bitbucket.org/chromiumembedded/cef/issues/3213/ozone-egl-initialization-does-not-have
+            // Desktop GL force makes Chromium not try to load its own ANGLE/Swiftshader so load paths aren't problematic.
+            if (OperatingSystem.IsLinux())
+                commandLine.AppendSwitch("--use-gl", "desktop");
+            
             // commandLine.AppendSwitch("--single-process");
 
             //commandLine.AppendSwitch("--disable-gpu");

Robust.Client.WebView/Cef/WebViewManagerCef.cs

@@ -26,6 +26,12 @@ namespace Robust.Client.WebView.Cef
                 throw new NotSupportedException("Unsupported platform for CEF!");
 
             var subProcessPath = PathHelpers.ExecutableRelativeFile(subProcessName);
+            var cefResourcesPath = LocateCefResources();
+
+            // System.Console.WriteLine(AppContext.GetData("NATIVE_DLL_SEARCH_DIRECTORIES"));
+
+            if (cefResourcesPath == null)
+                throw new InvalidOperationException("Unable to locate cef_resources directory!");
 
             var settings = new CefSettings()
             {
@@ -33,23 +39,13 @@ namespace Robust.Client.WebView.Cef
                 ExternalMessagePump = false, // Unsure, honestly. TODO CEF: Research this?
                 NoSandbox = true, // Not disabling the sandbox crashes CEF.
                 BrowserSubprocessPath = subProcessPath,
-                LocalesDirPath = Path.Combine(PathHelpers.GetExecutableDirectory(), "locales"),
-                ResourcesDirPath = PathHelpers.GetExecutableDirectory(),
-                RemoteDebuggingPort = 9222
+                LocalesDirPath = Path.Combine(cefResourcesPath, "locales"),
+                ResourcesDirPath = cefResourcesPath,
+                RemoteDebuggingPort = 9222,
             };
 
             Logger.Info($"CEF Version: {CefRuntime.ChromeVersion}");
 
-            // --------------------------- README --------------------------------------------------
-            // By the way! You're gonna need the CEF binaries in your client's bin folder.
-            // More specifically, version cef_binary_94.4.1+g4b61a8c+chromium-94.0.4606.54
-            // Windows: https://cef-builds.spotifycdn.com/cef_binary_94.4.1%2Bg4b61a8c%2Bchromium-94.0.4606.54_windows64_minimal.tar.bz2
-            // Linux: https://cef-builds.spotifycdn.com/cef_binary_94.4.1%2Bg4b61a8c%2Bchromium-94.0.4606.54_linux64_minimal.tar.bz2
-            // Here's how to get it to work:
-            // 1. Copy all the contents of "Release" to the bin/Content.Client folder.
-            // 2. Copy all the contents of "Resources" to the bin/Content.Client folder.
-            // -------------------------------------------------------------------------------------
-
             _app = new RobustCefApp();
 
             // We pass no main arguments...
@@ -60,6 +56,37 @@ namespace Robust.Client.WebView.Cef
             // And nothing seemed to work. Odd.
         }
 
+        private static string? LocateCefResources()
+        {
+            if (ProbeDir(PathHelpers.GetExecutableDirectory(), out var path))
+                return path;
+
+
+            foreach (var searchDir in NativeDllSearchDirectories())
+            {
+                if (ProbeDir(searchDir, out path))
+                    return path;
+            }
+
+            return null;
+
+            static bool ProbeDir(string dir, out string path)
+            {
+                path = Path.Combine(dir, "cef_resources");
+                return Directory.Exists(path);
+            }
+        }
+
+        internal static string[] NativeDllSearchDirectories()
+        {
+            var sepChar = OperatingSystem.IsWindows() ? ';' : ':';
+
+            var searchDirectories = ((string)AppContext.GetData("NATIVE_DLL_SEARCH_DIRECTORIES")!)
+                .Split(sepChar, StringSplitOptions.RemoveEmptyEntries);
+
+            return searchDirectories;
+        }
+
         public void Update()
         {
             // Calling this makes CEF do its work, without using its own update loop.

Robust.Client.WebView/Robust.Client.WebView.csproj

@@ -16,6 +16,7 @@
   <ItemGroup>
     <PackageReference Include="JetBrains.Annotations" Version="2020.3.0" />
     <PackageReference Include="System.Drawing.Common" Version="5.0.2" />
+    <PackageReference Include="Robust.Natives.Cef" Version="95.7.14" />
   </ItemGroup>
 
   <ItemGroup>