[XRay][docs] Chrome Trace Viewer Instructions

This patch adds an example on how to generate a Chrome Trace Viewer
loadable trace from an XRay trace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340847 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed