After locking a profile and showing the User Manager, make Guest the active profile

After locking a profile and showing the User Manager, make Guest the active profile

This is particularly important on Mac, where unless we do this the Bookmarks/History
menu bar items will reflect the last active profile (which has now been locked).

On Windows this is a nice to have and to be consistent. Overall this adds an extra
layer of security that you won't accidentally open a locked profile's window.

BUG=412952
Committed: https://crrev.com/dd5b6a619317f1e93348a71e70062275bda8e8dc
Cr-Commit-Position: refs/heads/master@{#296187}

[noms (inactive), 2014-09-18 21:21:58]

Patchset #1 (id:1) has been deleted

[noms (inactive), 2014-09-18 21:31:25]

noms@chromium.org changed reviewers:
+ asvitkine@chromium.org

[noms (inactive), 2014-09-18 21:31:26]

Hi Alexei,

Given that we chatted the most about it, would you mind reviewing this before I
send it over for OWNERS stamps? Thanks!

[Alexei Svitkine (slow), 2014-09-19 15:33:37]

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/profiles/...
File chrome/browser/profiles/profiles_state.cc (right):

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/profiles/...
chrome/browser/profiles/profiles_state.cc:164: ProfileInfoCache& cache =
profile_manager->GetProfileInfoCache();
Nit: Const ref or ptr, please.

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/ui/cocoa/...
File chrome/browser/ui/cocoa/profiles/user_manager_mac.mm (right):

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/ui/cocoa/...
chrome/browser/ui/cocoa/profiles/user_manager_mac.mm:152: // happened after
locking a profile.
Is it possible to lock a profile after this window is shown?

If so, wouldn't this logic have to exist elsewhere too? (If it's already handled
somewhere, please expand the comment to mention how that works.)

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/ui/cocoa/...
chrome/browser/ui/cocoa/profiles/user_manager_mac.mm:156: AppController*
controller = [NSApp delegate];
Use base::mac::ObjCCast<AppController>() instead of an implicit cast.

[noms (inactive), 2014-09-22 15:36:04]

Patchset #3 (id:60001) has been deleted

[noms (inactive), 2014-09-22 15:39:46]

Addressed comments + made some extra things in the ProfileInfoCache const, to be
able to define it as a const ref (no reason why they weren't const in the first
place). Also bungled it and sneaked in a rebase by accident :(

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/profiles/...
File chrome/browser/profiles/profiles_state.cc (right):

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/profiles/...
chrome/browser/profiles/profiles_state.cc:164: ProfileInfoCache& cache =
profile_manager->GetProfileInfoCache();
On 2014/09/19 15:33:36, Alexei Svitkine wrote:
> Nit: Const ref or ptr, please.

Done.

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/ui/cocoa/...
File chrome/browser/ui/cocoa/profiles/user_manager_mac.mm (right):

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/ui/cocoa/...
chrome/browser/ui/cocoa/profiles/user_manager_mac.mm:152: // happened after
locking a profile.
Yes. You could leave this window open (it's not modal), and lock a different
profile. That would trigger the code in UserManagerMac::Show where the instance
exists, and we still call the UserManagerWindowController -show method here. 

I am not sure whether this is relevant to this comment -- whether you activate
the window or create it from scratch, you still end up in this function.

On 2014/09/19 15:33:37, Alexei Svitkine wrote:
> Is it possible to lock a profile after this window is shown?
> 
> If so, wouldn't this logic have to exist elsewhere too? (If it's already
handled
> somewhere, please expand the comment to mention how that works.)

https://codereview.chromium.org/585653002/diff/40001/chrome/browser/ui/cocoa/...
chrome/browser/ui/cocoa/profiles/user_manager_mac.mm:156: AppController*
controller = [NSApp delegate];
On 2014/09/19 15:33:36, Alexei Svitkine wrote:
> Use base::mac::ObjCCast<AppController>() instead of an implicit cast.

Done.

[Alexei Svitkine (slow), 2014-09-22 16:58:00]

LGTM

https://codereview.chromium.org/585653002/diff/80001/chrome/browser/profiles/...
File chrome/browser/profiles/profiles_state.cc (right):

https://codereview.chromium.org/585653002/diff/80001/chrome/browser/profiles/...
chrome/browser/profiles/profiles_state.cc:172: CHECK(guest_profile);
Nit: DCHECK().

If it's NULL, it will crash on line 177 anyway, so no need for CHECK here.

[noms (inactive), 2014-09-22 17:30:06]

noms@chromium.org changed reviewers:
+ sky@chromium.org

[noms (inactive), 2014-09-22 17:30:06]

Hi Scott,

Could you please do an OWNERS review for c/b/app_controller_mac* (Alexei already
reviewed it) and a review on c/b/ui/views/? Thanks!

[sky, 2014-09-22 20:44:20]

LGTM

[noms (inactive), 2014-09-22 21:41:49]

https://codereview.chromium.org/585653002/diff/80001/chrome/browser/profiles/...
File chrome/browser/profiles/profiles_state.cc (right):

https://codereview.chromium.org/585653002/diff/80001/chrome/browser/profiles/...
chrome/browser/profiles/profiles_state.cc:172: CHECK(guest_profile);
On 2014/09/22 16:58:00, Alexei Svitkine wrote:
> Nit: DCHECK().
> 
> If it's NULL, it will crash on line 177 anyway, so no need for CHECK here.

Done.

[noms (inactive), 2014-09-22 21:41:56]

The CQ bit was checked by noms@chromium.org

[noms (inactive), 2014-09-22 21:41:56]

The CQ bit was unchecked by noms@chromium.org

[noms (inactive), 2014-09-22 21:41:57]

The CQ bit was checked by noms@chromium.org

[commit-bot: I haz the power, 2014-09-22 21:43:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/585653002/100001

[commit-bot: I haz the power, 2014-09-22 23:17:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-09-22 23:17:46]

Try jobs failed on following builders:
  mac_chromium_rel_swarming on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[noms (inactive), 2014-09-23 14:05:37]

The CQ bit was checked by noms@chromium.org

[commit-bot: I haz the power, 2014-09-23 14:27:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/585653002/120001

[commit-bot: I haz the power, 2014-09-23 15:20:27]

Committed patchset #5 (id:120001) as f2cadec73f73415af6a28023af6c8142834b7d26

[commit-bot: I haz the power, 2014-09-23 15:21:03]

Patchset 5 (id:??) landed as
https://crrev.com/dd5b6a619317f1e93348a71e70062275bda8e8dc
Cr-Commit-Position: refs/heads/master@{#296187}