remove ViewletDescriptor.isGlobal since it is unused

src/vs/workbench/browser/parts/activitybar/activitybarPart.ts

@@ -147,7 +147,6 @@ export class ActivitybarPart extends Part implements IActivityService {
 
 		// Add to viewlet switcher
 		this.compositeSwitcherBar.push(allViewletActions
-			.filter(v => !v.isGlobal)
 			.sort((v1, v2) => v1.order - v2.order)
 			.map(toAction)
 			, actionOptions);

src/vs/workbench/browser/viewlet.ts

@@ -152,11 +152,9 @@ export abstract class ViewerViewlet extends Viewlet {
  * A viewlet descriptor is a leightweight descriptor of a viewlet in the workbench.
  */
 export class ViewletDescriptor extends CompositeDescriptor<Viewlet> {
-	public isGlobal: boolean;
 
-	constructor(moduleId: string, ctorName: string, id: string, name: string, cssClass?: string, order?: number, isGlobal?: boolean) {
+	constructor(moduleId: string, ctorName: string, id: string, name: string, cssClass?: string, order?: number) {
 		super(moduleId, ctorName, id, name, cssClass, order);
-		this.isGlobal = isGlobal || false;
 	}
 }