fix: fix duplicated injected style tags when using shadow dom

We are currently checking that the style element exists in the shadow dom to decide if it already exists in the head

Author: Loïc Mangeonjean

vscode-patches/0064-feat-support-shadow-dom.patch

@@ -37,8 +37,8 @@ Subject: [PATCH] feat: support shadow dom
  .../contrib/terminal/browser/terminalView.ts  |  2 +-
  .../browser/gettingStarted.ts                 |  4 ++--
  .../browser/walkThroughPart.ts                |  6 ++---
- .../themes/browser/workbenchThemeService.ts   |  4 ++--
- 34 files changed, 102 insertions(+), 68 deletions(-)
+ .../themes/browser/workbenchThemeService.ts   |  2 +-
+ 34 files changed, 101 insertions(+), 67 deletions(-)
 
 diff --git a/src/vs/base/browser/dom.ts b/src/vs/base/browser/dom.ts
 index 1c7c66f76aa..f414f2b07fd 100644
@@ -840,24 +840,15 @@ index 27d04d09f01..61c2b58dfa4 100644
  			active = active.parentElement;
  		}
 diff --git a/src/vs/workbench/services/themes/browser/workbenchThemeService.ts b/src/vs/workbench/services/themes/browser/workbenchThemeService.ts
-index d85b23015f4..d7d186e8234 100644
+index d85b23015f4..a9dc7c145e0 100644
 --- a/src/vs/workbench/services/themes/browser/workbenchThemeService.ts
 +++ b/src/vs/workbench/services/themes/browser/workbenchThemeService.ts
-@@ -18,7 +18,7 @@ import { Event, Emitter } from '../../../../base/common/event.js';
- import { registerFileIconThemeSchemas } from '../common/fileIconThemeSchema.js';
- import { IDisposable, Disposable, DisposableStore } from '../../../../base/common/lifecycle.js';
- import { FileIconThemeData, FileIconThemeLoader } from './fileIconThemeData.js';
--import { createStyleSheet } from '../../../../base/browser/domStylesheets.js';
-+import { createStyleSheet, shadowRootContainer } from '../../../../base/browser/domStylesheets.js';
- import { IBrowserWorkbenchEnvironmentService } from '../../environment/browser/environmentService.js';
- import { IFileService, FileChangeType } from '../../../../platform/files/common/files.js';
- import { URI } from '../../../../base/common/uri.js';
 @@ -793,7 +793,7 @@ class ThemeFileWatcher {
  }
 
  function _applyRules(styleSheetContent: string, rulesClassName: string) {
 -	const themeStyles = mainWindow.document.head.getElementsByClassName(rulesClassName);
-+	const themeStyles = (shadowRootContainer ?? mainWindow.document.head).querySelectorAll(`.${rulesClassName}`);
++	const themeStyles = mainWindow.document.head.querySelectorAll(`.${rulesClassName}`);
  	if (themeStyles.length === 0) {
  		const elStyle = createStyleSheet();
  		elStyle.className = rulesClassName;