请在安全管道中使用santizer，然后添加如下链接

Please use santizer with safe pipe and then include the link as below

<iframe class="doc" src="https://docs.google.com/gview?url=https://subtreebucket.s3.amazonaws.com/docsFile_1559124133664_dummy.pdf&embedded=true"></iframe>

在iframe中添加源代码时，请确保您使用的是Embedded = true.肯定会的

Make sure you are using embedded=true while adding source in the iframe. It'll definitely work