Migrate most EventEmitter to base/ Emitter

src/browser/services/ThemeService.ts

@@ -7,10 +7,10 @@ import { ColorContrastCache } from 'browser/ColorContrastCache';
 import { IThemeService } from 'browser/services/Services';
 import { DEFAULT_ANSI_COLORS, IColorContrastCache, IColorSet, ReadonlyColorSet } from 'browser/Types';
 import { color, css, NULL_COLOR } from 'common/Color';
-import { EventEmitter } from 'common/EventEmitter';
 import { Disposable } from 'common/Lifecycle';
 import { IOptionsService, ITheme } from 'common/services/Services';
 import { AllColorIndex, IColor, SpecialColorIndex } from 'common/Types';
+import { Emitter } from 'vs/base/common/event';
 
 interface IRestoreColorSet {
   foreground: IColor;
@@ -40,7 +40,7 @@ export class ThemeService extends Disposable implements IThemeService {
 
   public get colors(): ReadonlyColorSet { return this._colors; }
 
-  private readonly _onChangeColors = this.register(new EventEmitter<ReadonlyColorSet>());
+  private readonly _onChangeColors = this.register(new Emitter<ReadonlyColorSet>());
   public readonly onChangeColors = this._onChangeColors.event;
 
   constructor(