removed drawingBuffer from particle size to fix pixelRatio issues
removed drawingBuffer from particle size to fix pixelRatio issues

CesiumGS/cesium,likangning93/cesium,YonatanKra/cesium,CesiumGS/cesium,CesiumGS/cesium,CesiumGS/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,progsung/cesium,likangning93/cesium,likangning93/cesium,progsung/cesium,CesiumGS/cesium,YonatanKra/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,YonatanKra/cesium,YonatanKra/cesium