google/tracing-framework — pull request #515 by rsturgell (2014-09-25 06:24:57+00:00)
Title: Fix race condition in sendSnapshotToPage_.

There are two asyncronous events that occur when a snapshot is
requested: the child window is opened, and the buffers are collected.
They can complete in either order, but currently if the page manages to
open and do the postMessage before the data is available, then we never
find out about the child.

This is fixed by introducing a Result for the child channel.