handleFloatTileLoaded_(floatTile, coord, tileId, div) {
    this.floatTiles_.set(coord, floatTile);
    this.floatTileDivs_.set(coord, div);
    goog.array.remove(this.tilesLoading, tileId);
    this.dispatchTileEvent_();
  }
Handles float tile loaded events by storing the tile data and dispatching
a tile event.
@param {Float32Array} floatTile Successfully requested float tile
@param {google.maps.Point} coord Coordinate of the floating tile
@param {string} tileId Unique tile ID
@param {!Element} div The corresponding DIV element.
@private