snapshot: Make destructors of interface classes public and virtual

snapshot: Make destructors of interface classes public and virtual.

R=rsesek@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/4ee00568b72e2aa25c262f2d46aacca36bddcffb

[Mark Mentovai, 2014-10-29 17:46:11]

mark@chromium.org changed reviewers:
+ rsesek@chromium.org

[Mark Mentovai, 2014-10-29 17:46:12]

You’re going to like this one a lot.

I wanted the TestSnapshot* family to work with base class pointers so that, for
example, a TestThreadSnapshot object would own a MemorySnapshot* instead of a
TestMemorySnapshot*. Since that means that some of these objects will need to be
deleted through base class pointers, the destructors need to become public and
virtual.

[Robert Sesek, 2014-10-29 20:53:12]

LGTM

[Mark Mentovai, 2014-10-29 21:31:31]

Committed patchset #1 (id:1) manually as
4ee00568b72e2aa25c262f2d46aacca36bddcffb (presubmit successful).