The emailed file is now a zipfile containing one .ahprof
file for each process known to MemoryTracker.
Change-Id: If4a73df9afd38756cc01ff37b2d249346e5f7e9f
Multiple processes may be tracked and viewed simultaneously.
Also, some changes to the graph:
* show uss and pss together
* adjust opacity controls
Change-Id: I20eebaa8cc8faf78b46af2a35d71ee538207f02b