decrease the net log frequency by cache the read length

When read bytes from network, chromium will generate a log for each
read operation. and each read length is about 1k~4k. So read a 10Mbps
1080P video clip will generate too many log events per second.

This event logging request exist in release build and develop build.
For desktop, this action maybe light, but for Android devices, this action
will make CPU more busy.

Change-Id: I412c74798ff742f79dad9cbac95cb1c0d3209727
Author: Xuefeng Deng <xuefeng.deng@intel.com>
Singed-off-by: Shuo Gao <shuo.gao@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Signed-off-by: Jack Ren <jack.ren@intel.com>
Author-tracking-BZ: 35737