[Bug fix] Do zero check on the value to be a denominator in incoming DEFLATE ratio calculation.
[Bug fix] Do zero check on the value to be a denominator in incoming DEFLATE ratio calculation.

Release note: same as CL title
Review URL: https://codereview.appspot.com/8408043

git-svn-id: d23f85197b9dafcb1b1682eb9d0eda70517bdc52@746 4ff78f4a-9131-11de-b045-6380ec9940d4

bpsinc-native/src_third_party_pywebsocket_src,bpsinc-native/src_third_party_pywebsocket_src,bpsinc-native/src_third_party_pywebsocket_src,bpsinc-native/src_third_party_pywebsocket_src