Correctly dispose of Renderer and ScreenDprMonitor

src/renderer/Types.ts

@@ -4,7 +4,7 @@
  */
 
 import { ITerminal } from '../Types';
-import { IEventEmitter, ITheme } from 'xterm';
+import { IEventEmitter, ITheme, IDisposable } from 'xterm';
 import { IColorSet } from '../shared/Types';
 
 /**
@@ -24,10 +24,11 @@ export const enum FLAGS {
  * Note that IRenderer implementations should emit the refresh event after
  * rendering rows to the screen.
  */
-export interface IRenderer extends IEventEmitter {
+export interface IRenderer extends IEventEmitter, IDisposable {
   dimensions: IRenderDimensions;
   colorManager: IColorManager;
 
+  dispose(): void;
   setTheme(theme: ITheme): IColorSet;
   onWindowResize(devicePixelRatio: number): void;
   onResize(cols: number, rows: number): void;