Add new conversion method to ConfirmInfoBarDelegate

Add new conversion method to ConfirmInfoBarDelegate

Add AsNativeAppInfoBarDelegate() method to ConfirmInfoBarDelegate to
allow casting to NativeAppInfoBarDelegate on iOS.

Cleanup code by using nullptr instead of NULL.

BUG=438238
Committed: https://crrev.com/4a2bfc6a086f61a76637359a5904a58cdc0730a4
Cr-Commit-Position: refs/heads/master@{#310344}

[sdefresne, 2015-01-06 15:43:34]

sdefresne@chromium.org changed reviewers:
+ pkasting@chromium.org

[sdefresne, 2015-01-06 15:43:34]

pkasting: please take a look. The NativeAppInfoBarDelegate is not yet
upstreamed, but I'd like to introduce this change soon instead of keeping a fork
downstream if possible.

droger: FYI

[Peter Kasting, 2015-01-06 20:48:08]

Can the downstream code just static_cast?  If it knows the target type, it can
do that instead of adding this oracle -- we try to only add these oracles where
a caller needs the equivalent of RTTI.

[sdefresne, 2015-01-06 22:55:48]

On 2015/01/06 at 20:48:08, pkasting wrote:
> Can the downstream code just static_cast?  If it knows the target type, it can
do that instead of adding this oracle -- we try to only add these oracles where
a caller needs the equivalent of RTTI.

This is used downstream in the implementation of
NativeAppInfoBarDelegate::EqualsDelegate(). AFAICT this needs some kind of RTTI
or oracles to be implemented as the call to InfoBarDelegate::EqualsDelegate() is
made in InfoBarManager::AddInfoBar() and the type InfoBarDelegate is not
statically known there.

[Peter Kasting, 2015-01-06 23:34:20]

On 2015/01/06 22:55:48, sdefresne wrote:
> On 2015/01/06 at 20:48:08, pkasting wrote:
> > Can the downstream code just static_cast?  If it knows the target type, it
can
> do that instead of adding this oracle -- we try to only add these oracles
where
> a caller needs the equivalent of RTTI.
> 
> This is used downstream in the implementation of
> NativeAppInfoBarDelegate::EqualsDelegate(). AFAICT this needs some kind of
RTTI
> or oracles to be implemented as the call to InfoBarDelegate::EqualsDelegate()
is
> made in InfoBarManager::AddInfoBar() and the type InfoBarDelegate is not
> statically known there.

Is there a link where I can see what your implementation of EqualsDelegate()
looks like?  I assume you're doing something beyond simple pointer
comparisons...

This is probably fine, I'd just like to make sure it's the optimal way.

[Peter Kasting, 2015-01-07 18:58:47]

OK.  LGTM.

[sdefresne, 2015-01-07 19:02:01]

Thank you.

[sdefresne, 2015-01-07 19:02:05]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2015-01-07 19:03:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/833413002/1

[commit-bot: I haz the power, 2015-01-07 19:55:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-07 19:56:53]

Patchset 1 (id:??) landed as
https://crrev.com/4a2bfc6a086f61a76637359a5904a58cdc0730a4
Cr-Commit-Position: refs/heads/master@{#310344}