Custom Windows Webview2 Args (#4467)

* Adding the ability to pass custom args to windows webview2

---------

Co-authored-by: Jason Gibson <jason@harbingerinteractive.com>
Co-authored-by: Lea Anthony <lea.anthony@gmail.com>

v3/UNRELEASED_CHANGELOG.md

@@ -15,7 +15,9 @@ This file is automatically processed by the nightly release workflow.
 After processing, the content will be moved to the main changelog and this file will be reset.
 -->
 
-### Added
+## Added
+<!-- New features, capabilities, or enhancements -->
+- Added `AdditionalLaunchArgs` to `WindowsWindow` options to allow for additional command line arguments to be passed to the WebView2 browser. in [PR](https://github.com/wailsapp/wails/pull/4467)
 - Added Run go mod tidy automatically after wails init [@triadmoko](https://github.com/triadmoko) in [PR](https://github.com/wailsapp/wails/pull/4286)
 - Windows Snapassist feature by @leaanthony in [PR](https://github.dev/wailsapp/wails/pull/4463)
 

v3/pkg/application/webview_window_options.go

@@ -292,13 +292,15 @@ type WindowsWindow struct {
 	// PasswordAutosaveEnabled enables autosaving passwords
 	PasswordAutosaveEnabled bool
 
-	// EnabledFeatures and DisabledFeatures are used to enable or disable specific features in the WebView2 browser.
+	// EnabledFeatures, DisabledFeatures and AdditionalLaunchArgs are used to enable or disable specific features in the WebView2 browser.
 	// Available flags: https://learn.microsoft.com/en-us/microsoft-edge/webview2/concepts/webview-features-flags?tabs=dotnetcsharp#available-webview2-browser-flags
 	// WARNING: Apps in production shouldn't use WebView2 browser flags,
 	// because these flags might be removed or altered at any time,
 	// and aren't necessarily supported long-term.
-	EnabledFeatures  []string
-	DisabledFeatures []string
+	// AdditionalLaunchArgs should always be preceded by "--"
+	EnabledFeatures      []string
+	DisabledFeatures     []string
+	AdditionalLaunchArgs []string
 }
 
 type Theme int

v3/pkg/application/webview_window_windows.go

@@ -1798,6 +1798,10 @@ func (w *windowsWebviewWindow) setupChromium() {
 		chromium.AdditionalBrowserArgs = append(chromium.AdditionalBrowserArgs, arg)
 	}
 
+	if len(opts.AdditionalLaunchArgs) > 0 {
+		chromium.AdditionalBrowserArgs = append(chromium.AdditionalBrowserArgs, opts.AdditionalLaunchArgs...)
+	}
+
 	chromium.DataPath = globalApplication.options.Windows.WebviewUserDataPath
 	chromium.BrowserPath = globalApplication.options.Windows.WebviewBrowserPath