Implement window.alert() and its cousins for extensions....

Implement window.alert() and its cousins for extensions.
Second try, now with fixed observer.

BUG=12126
TEST=put a window.prompt() in a background page, a browser action, and a page action.
Make sure it gets the result back correctly. Also make sure it still works when
called from a web page.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=31204

[Pam (message me for reviews), 2009-11-06 01:34:44]

Matt: Please re-review.
Tony: FYI in case there was a reason AppModalDialog was observing all sources,
although it seems unlikely.

This should fix browser_tests.

The differences between the previous version of this patch
(http://codereview.chromium.org/341089) and this one are in app_modal_dialog.h
and .cc:
* To fix the bug, use a tab_contents_ member variable rather than accessing
client_->AsTabContents() each time.
* To be more efficient, only observe our own TabContents and
NavigationController.

[tony, 2009-11-06 01:36:48]

On 2009/11/06 01:34:44, Pam wrote:
> Tony: FYI in case there was a reason AppModalDialog was observing all sources,
> although it seems unlikely.

I don't think there was any reason for this.  I think erg was the original
author-- I just refactored when bringing up modal dialogs on Linux.  It's
probably fine to narrow the scope.

[Matt Perry, 2009-11-06 01:45:42]

lgtm

http://codereview.chromium.org/373006/diff/1/6
File chrome/browser/app_modal_dialog.cc (right):

http://codereview.chromium.org/373006/diff/1/6#newcode23
Line 23: tab_contents_(client->AsTabContents()),
nit: I don't think you actually need to cache this, since you no longer use the
client_ pointer during destruction (since Observe is called only for this tab).

http://codereview.chromium.org/373006/diff/1/6#newcode44
Line 44: skip_this_dialog_ = true;
maybe you should NULL out client_ and tab_contents_ here, since they'll both be
invalid anyway.

[Pam (message me for reviews), 2009-11-06 01:56:19]

Thanks, I'll land this as soon as it passes the trybots.

http://codereview.chromium.org/373006/diff/1/6
File chrome/browser/app_modal_dialog.cc (right):

http://codereview.chromium.org/373006/diff/1/6#newcode23
Line 23: tab_contents_(client->AsTabContents()),
On 2009/11/06 01:45:42, Matt Perry wrote:
> nit: I don't think you actually need to cache this, since you no longer use
the
> client_ pointer during destruction (since Observe is called only for this
tab).

Duh, of course. tab_contents_ pulled back out.

http://codereview.chromium.org/373006/diff/1/6#newcode44
Line 44: skip_this_dialog_ = true;
On 2009/11/06 01:45:42, Matt Perry wrote:
> maybe you should NULL out client_ and tab_contents_ here, since they'll both
be
> invalid anyway.

Sure, done.