minidump: Change the ownership model

minidump: Change the ownership model.

All minidump objects now own their all of their children, rather than
having them maintain weak pointers and requiring callers to maintain
ownership.

The only weak object in the entire tree now is the “extra memory” added
to a MinidumpMemoryListWriter by its AddExtraMemory() method. Extra
memory aliases objects owned elsewhere in the tree, typically by a
MinidumpThreadWriter as stack memory. Non-“extra” memory added to a
MinidumpMemoryListWriter by its AddMemory() method is strongly owned.

Many objects are now deleted through base pointers, and in those cases,
the base classes now have public virtual destructors. The ultimate base,
MinidumpWritable, is still protected to guard against direct
instantiation and deletion, and thus its destructor does not need to be
virtual.

This updates mini_chromium to eeb3b6a4f020 specifically for that
revision, which includes necessary updates to scoped_ptr. It also picks
up:

eeb3b6a4f020 Update base/move.h and base/memory/scoped_ptr.h to match
67ad2efafaba More porting to Windows
be27a006421e AUTHORS: Fix link post-git migration flag day.
05f5b1503230 Add codereview.settings to mini_chromium.
a32c2b199811 Beginnings of Windows support in mini_chromium

TEST=minidump_test
R=rsesek@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/0a4ea0b52dc98083bef0f8521e347172214e6846

[Mark Mentovai, 2014-10-24 17:07:52]

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

[Robert Sesek, 2014-10-27 17:18:00]

The styleguide explicitly says "If your class has virtual methods, its
destructor should be virtual.", so ~MinidumpWritable should be virtual.

http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Inheritance

https://codereview.chromium.org/674153002/diff/60001/minidump/minidump_memory...
File minidump/minidump_memory_writer.h (right):

https://codereview.chromium.org/674153002/diff/60001/minidump/minidump_memory...
minidump/minidump_memory_writer.h:42: virtual ~MinidumpMemoryWriter();
I believe this should be override as well.

https://codereview.chromium.org/674153002/diff/60001/minidump/minidump_stream...
File minidump/minidump_stream_writer.h (right):

https://codereview.chromium.org/674153002/diff/60001/minidump/minidump_stream...
minidump/minidump_stream_writer.h:34: virtual ~MinidumpStreamWriter();
Same: override.

[Mark Mentovai, 2014-10-27 18:44:11]

Patchset #5 (id:80001) has been deleted

[Mark Mentovai, 2014-10-27 18:48:45]

That bit of the style guide is a relic from when -Wnon-virtual-dtor was the best
warning a compiler could provide, but that’s no longer true in light of language
and compiler improvements. Nevertheless, here’s a version that does what you
ask.

[Robert Sesek, 2014-10-27 18:59:52]

LGTM

On 2014/10/27 18:48:45, Mark Mentovai wrote:
> That bit of the style guide is a relic from when -Wnon-virtual-dtor was the
best
> warning a compiler could provide, but that’s no longer true in light of
language
> and compiler improvements. Nevertheless, here’s a version that does what you
> ask.

It may be an unnecessary relic technology wise, but that section of the guide
was updated recently for override and final, yet the advice stands. I think it's
easier to reason about the correctness of the other overrides when following
this advice. I view this similarly to the mini-discussion we had about calling a
base class' ctor from the derived ctor's initializer list for extra
specificity/clarity.

[Mark Mentovai, 2014-10-27 19:01:48]

Committed patchset #5 (id:100001) manually as
0a4ea0b52dc98083bef0f8521e347172214e6846 (presubmit successful).