selenium操作H5页面，自定义Chrome的Mobile emulation。

selelnium操作H5页面，有时候需要宽屏模式的页面，可以使用 deviceMetrics 参数来自定义H5页面宽高。

WIDTH = 1080
HEIGHT = 1000
PIXEL_RATIO = 3.0
USERAGENT= 'Mozilla/5.0 (iPhone; CPU iPhone OS 13_2_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.3 Mobile/15E148 Safari/604.1'
        mobileEmulation = {'deviceMetrics': {"width": WIDTH, "height": HEIGHT, "pixelRatio": PIXEL_RATIO},"userAgent": USERAGENT}

chrome_options = webdriver.ChromeOptions()
chrome_options.add_experimental_option('mobileEmulation', mobileEmulation)