libchromeos: Add ability to pass timeout to Stream::WaitForDataBlocking

To control the timeout when performing blocking I/O, added a |timeout|
parameter to Stream::WaitForDataBlocking.

BUG=brillo:1162
TEST=`FEATURES=test emerge-link libchromeos`

Change-Id: Icee2f7b0a8a93daf15b05bf5fbee2a4ec9410a17
Reviewed-on: https://chromium-review.googlesource.com/275027
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
20 files changed