Download the Windows 10 SDK (this works on older versions of Windows as well): https://dev.windows.com/en-us/downloads/windows-10-sdk
Update: The version of WPT that gets installed using latest Win 10 SDK no longer works on Win7. Bruce Dawson's UIforETW will detect if you installed the new incompatible version and will uninstall it for you, and then install the proper one. It can be downloaded here: https://github.com/google/UIforETW/releases
Make sure Windows Performance Toolkit is checked (I usually just install everything).
Navigate to: C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit\gpuview
Replace log.cmd with the contents from here:
(This just adds the TRACE_VR lines with the guid we use for tracking events in SteamVR).
(If you are using the Win8.1 ADK: http://pastebin.com/jEWDMbhz)
Open a command prompt at this location with Admin privileges.
Input "log.cmd"(Without Quotes) to start capturing. (Tested only with Windows 7)
Wait maybe a second once it gets through loading things (the captured data size adds up fast!).
Then run "log.cmd"(Without Quotes) again to stop capturing (followed by a rather lengthy merge process).
Run 'gpuview' and select merged.etl to view.