Fix IdentifyChromeProcesses.py to group browsers by type.
Fix IdentifyChromeProcesses.py to group browsers by type.

When working on Chrome I may end up with two or three versions
running simultaneously - the stable version that I use for email and
bug triage, and the locally built version that I am testing. Having
all of the PIDs grouped together (two browsers, two gpu-process) is
confusing, so now I group them by exePath.

This doesn't work perfectly if the test browser is launched through a
relative path, but that is a minor (and indeed avoidable) glitch.

OSVR/UIforETW,ariccio/UIforETW,ariccio/UIforETW,u-engine/UIforETW,modulexcite/UIforETW,mwinterb/UIforETW,OSVR/UIforETW,google/UIforETW,ariccio/UIforETW,modulexcite/UIforETW,google/UIforETW,modulexcite/UIforETW,u-engine/UIforETW,MikeMarcin/UIforETW,MikeMarcin/UIforETW,ariccio/UIforETW,google/UIforETW,OSVR/UIforETW,MikeMarcin/UIforETW,mwinterb/UIforETW,u-engine/UIforETW,mwinterb/UIforETW,google/UIforETW