message: Properly cache `FontAtlas` objects inside the `FontAtlasRepository`
diff: @@ -24,8 +24,7 @@ export class FontAtlasRepository {
  }
  const fontAtlas = new FontAtlasImpl(metrics);
  - this._refCount.set(key, 1);
  - return {
  + const disposableFontAtlas: FontAtlas & Disposable = {
  drawCodePoint: fontAtlas.drawCodePoint.bind(fontAtlas),
  dispose: () => {
  @@ -37,6 +36,9 @@ export class FontAtlasRepository {
  }
  }
  };
  + this._refCount.set(key, 1);
  + this._map.set(key, disposableFontAtlas);
  + return disposableFontAtlas;
  }
  private _key(metrics: MonospaceFontMetrics): string {
  