If the "record allocation stack traces" feature is enabled, it would be very useful if the "diff" feature (also known as
"liveness comparison", or "compute the difference between two comparable memory snapshots") could be decomposable by
allocation stack trace hierarchy.  This would help tremendously in detecting the source of memory leaks.

For example, every line in the current "Liveness Comparison" window shows a difference in bytes.  In the proposed
feature, every line would have a "+" next to its name, which would drill down into the differences in bytes, by
allocation stack trace paths.

Example:

- char[]                                +1,774,089 bytes
  + java.util.Arrays.copyOfRange(...)     +963,334 bytes
  + java.util.Arrays.copyOf(...)          +634,931 bytes
  + ...
  + ...