Fixing the BeforeUnloadEvent

Fixing the BeforeUnloadEvent

Basically the last Blink upgrade introduced the BeforeUnloadEvent which conflicted with our previous polyfill. Our definition was removed, but the suppression remained for Event.returnValue.

The suppression is still needed since that's the incorrect type and on the wrong class, so I modified our metadata lookup to allow it to only target exact class matches (and not super classes).
BUG=
R=efortuna@google.com, vsm@google.com

Committed: https://code.google.com/p/dart/source/detail?r=29752

[Emily Fortuna, 2013-10-31 22:03:41]

https://codereview.chromium.org/54913005/diff/30001/sdk/lib/html/dart2js/html...
File sdk/lib/html/dart2js/html_dart2js.dart (right):

https://codereview.chromium.org/54913005/diff/30001/sdk/lib/html/dart2js/html...
sdk/lib/html/dart2js/html_dart2js.dart:634: +  String get returnValue =>
JS("String", "#.returnValue", this);
can't returnValue just use the native keyword?

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
File tools/dom/scripts/htmlrenamer.py (right):

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
tools/dom/scripts/htmlrenamer.py:597: '!Event.returnValue',
accidental?

[blois, 2013-10-31 22:09:20]

https://codereview.chromium.org/54913005/diff/30001/sdk/lib/html/dart2js/html...
File sdk/lib/html/dart2js/html_dart2js.dart (right):

https://codereview.chromium.org/54913005/diff/30001/sdk/lib/html/dart2js/html...
sdk/lib/html/dart2js/html_dart2js.dart:634: +  String get returnValue =>
JS("String", "#.returnValue", this);
On 2013/10/31 22:03:42, Emily Fortuna wrote:
> can't returnValue just use the native keyword?

Yes, but this is auto-generated. It's making this odd syntax because it's still
treating it as shadowing even though the base has been suppressed (hence the
shadowing definition comment).

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
File tools/dom/scripts/htmlrenamer.py (right):

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
tools/dom/scripts/htmlrenamer.py:597: '!Event.returnValue',
On 2013/10/31 22:03:42, Emily Fortuna wrote:
> accidental?

Nope- need to suppress returnValue on Event, but not on BeforeUnloadEvent, so
added this syntax. Not sure if it's the best prefix though.

See code below where support for it was added.

[vsm, 2013-10-31 22:15:41]

lgtm

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
File tools/dom/scripts/htmlrenamer.py (right):

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
tools/dom/scripts/htmlrenamer.py:597: '!Event.returnValue',
On 2013/10/31 22:09:21, blois wrote:
> On 2013/10/31 22:03:42, Emily Fortuna wrote:
> > accidental?
> 
> Nope- need to suppress returnValue on Event, but not on BeforeUnloadEvent, so
> added this syntax. Not sure if it's the best prefix though.

Maybe '=Event' - I think the JS magic function has similar for exact type match.

Can you add a comment here as to what it means either way?

> 
> See code below where support for it was added.

[blois, 2013-10-31 22:36:08]

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
File tools/dom/scripts/htmlrenamer.py (right):

https://codereview.chromium.org/54913005/diff/30001/tools/dom/scripts/htmlren...
tools/dom/scripts/htmlrenamer.py:597: '!Event.returnValue',
On 2013/10/31 22:15:41, vsm wrote:
> On 2013/10/31 22:09:21, blois wrote:
> > On 2013/10/31 22:03:42, Emily Fortuna wrote:
> > > accidental?
> > 
> > Nope- need to suppress returnValue on Event, but not on BeforeUnloadEvent,
so
> > added this syntax. Not sure if it's the best prefix though.
> 
> Maybe '=Event' - I think the JS magic function has similar for exact type
match.
> 
> Can you add a comment here as to what it means either way?
> 
> > 
> > See code below where support for it was added.
> 

Done.

[Emily Fortuna, 2013-10-31 22:36:42]

lgtm

[blois, 2013-11-01 16:17:50]

Committed patchset #2 manually as r29752 (presubmit successful).