Standardize usage of virtual/override/final in chrome/browser/notifications

Standardize usage of virtual/override/final in chrome/browser/notifications

The Google C++ style guide states:

  Explicitly annotate overrides of virtual functions or virtual
  destructors with an override or (less frequently) final specifier.
  Older (pre-C++11) code will use the virtual keyword as an inferior
  alternative annotation. For clarity, use exactly one of override,
  final, or virtual when declaring an override.

To better conform to these guidelines, the following constructs have
been rewritten:

- if a base class has a virtual destructor, then:
    virtual ~Foo();                   ->  ~Foo() override;
- virtual void Foo() override;        ->  void Foo() override;
- virtual void Foo() override final;  ->  void Foo() final;

This patch was automatically generated. The clang plugin can generate
fixit hints, which are suggested edits when it is 100% sure it knows how
to fix a problem. The hints from the clang plugin were applied to the
source tree using the tool in https://codereview.chromium.org/598073004.

BUG=417463
R=dewittj@chromium.org

Committed: https://crrev.com/45ccfbadf5bf0a02bfd402e24c24ac1f096f3a46
Cr-Commit-Position: refs/heads/master@{#300617}

[dewittj, 2014-10-21 22:04:32]

lgtm, but I wonder if there are any gotchas I should know about?  I'm not really
a C++11 expert so any advice would be welcome.  Thanks!

Also feel free to convert ui/message_center as well.

[dcheng, 2014-10-21 22:07:30]

No real catches to know of--it's basically the same deal as before, but with the
official C++11 version. The only change is you should only use one of
{virtual,override,final}, whereas before you'd use virtual OVERRIDE.

Finally, some people like to use final in all their derived classes with no
subclasses, but that's not really the convention in Chrome (as far as I can
tell).

[dcheng, 2014-10-21 22:07:34]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2014-10-21 22:08:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/667283002/1

[commit-bot: I haz the power, 2014-10-22 01:58:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-22 04:05:21]

Patchset 1 (id:??) landed as
https://crrev.com/45ccfbadf5bf0a02bfd402e24c24ac1f096f3a46
Cr-Commit-Position: refs/heads/master@{#300617}