src/vs/workbench/browser/parts/editor/textDiffEditor.ts/TextDiffEditor/scopedContextKeyService
class TextDiffEditor:	override get scopedContextKeyService(): IContextKeyService | undefined {
		if (!this.diffEditorControl) {
			return undefined;
		}

		const originalEditor = this.diffEditorControl.getOriginalEditor();
		const modifiedEditor = this.diffEditorControl.getModifiedEditor();

		return (originalEditor.hasTextFocus() ? originalEditor : modifiedEditor).invokeWithinContext(accessor => accessor.get(IContextKeyService));
	}