Add MinidumpCrashpadInfo::report_id

Add MinidumpCrashpadInfo::report_id.

Now that Chrome’s about:crashes displays the crash report UUID, I wanted
to add it to the minidump. In the future, we may be able to index these
on the server. This will also help identify dumps that correspond to the
same event once we’re equipped to convert between different formats.

Ideally, this new field is populated with the same UUID used locally in
the crash report database. To make this work,
CrashReportDatabase::NewReport must carry the UUID. This was actually
part of CrashReportDatabaseWin’s private extension to NewReport, so that
extension subclass can now be cleaned up.

TEST=crashpad_minidump_test MinidumpCrashpadInfoWriter.*,
     crashpad_client_test CrashReportDatabaseTest.NewCrashReport

R=rsesek@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/6bf80c3e48594d98f77a01bae8ec4bcc7bfc116d

[Mark Mentovai, 2015-03-13 15:21:35]

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

[Robert Sesek, 2015-03-13 16:18:23]

I think my only concern about this is that not all the Database calls are
guarded against taking a UUID from a report in the New state. I'm not sure what
would happen if a caller called PrepareNewReport() and then tried to use the
UUID from the NewReport struct in one of the other calls that takes just the
UUID.

[Mark Mentovai, 2015-03-13 16:24:12]

That should be OK with the Mac database because the report will only exist in
the “new” directory, which nothing else ever consults. If someone tried to use
the UUID there, it’d be a database error.

Similarly, on Windows, anything that needs to deal with the UUID operates on the
metadata file, but a report that’s only been started with
PrepareNewCrashReport() won’t have an entry in that file. The metadata’s only
created by FinishedWritingCrashReport().

[Robert Sesek, 2015-03-13 16:55:16]

LGTM

[Mark Mentovai, 2015-03-13 17:01:00]

Committed patchset #1 (id:1) manually as
6bf80c3e48594d98f77a01bae8ec4bcc7bfc116d (presubmit successful).