Further code review changes for issue 8341027.

Further code review changes for issue 8341027.

This passes a null pointer to EmptyStyleDeclaration's superclass constructor,
and ensures that DocumentFragment#style and
DocumentFragment#getBoundingClientRect are cached.

[Jacob, 2011-10-27 21:01:27]

http://codereview.chromium.org/8416010/diff/1/client/html/src/DOMWrapperBase....
File client/html/src/DOMWrapperBase.dart (right):

http://codereview.chromium.org/8416010/diff/1/client/html/src/DOMWrapperBase....
client/html/src/DOMWrapperBase.dart:10: // We should never be creating duplicate
wrappers.
because this is on the hot path for every time any wrapper is created, add a
second zero arg named constructor instead of adding the if.
The second constructor could actually be const which should allow
EmptyCSSStyleDeclaration to also be const and now that i think about it then
you'd be able to enable reuse of the EmptyCSSStyleDeclaration without caching
it.
e.g.

const DOMWrapperBase._empty() : _ptr = null;


then write 
const EmptyCSSStyleDeclaration();
instead of
new EmptyCSSStyleDeclaration()

[nweiz, 2011-10-27 21:20:35]

http://codereview.chromium.org/8416010/diff/1/client/html/src/DOMWrapperBase....
File client/html/src/DOMWrapperBase.dart (right):

http://codereview.chromium.org/8416010/diff/1/client/html/src/DOMWrapperBase....
client/html/src/DOMWrapperBase.dart:10: // We should never be creating duplicate
wrappers.
On 2011/10/27 21:01:27, jacobr wrote:
> because this is on the hot path for every time any wrapper is created, add a
> second zero arg named constructor instead of adding the if.
> The second constructor could actually be const which should allow
> EmptyCSSStyleDeclaration to also be const and now that i think about it then
> you'd be able to enable reuse of the EmptyCSSStyleDeclaration without caching
> it.
> e.g.
> 
> const DOMWrapperBase._empty() : _ptr = null;
> 
> 
> then write 
> const EmptyCSSStyleDeclaration();
> instead of
> new EmptyCSSStyleDeclaration()

Done.

[Jacob, 2011-10-27 21:35:43]

http://codereview.chromium.org/8416010/diff/1004/client/layout/layout.dart
File client/layout/layout.dart (right):

http://codereview.chromium.org/8416010/diff/1004/client/layout/layout.dart#ne...
client/layout/layout.dart:8: #import('../html/html.dart');
you accidentally uploaded with the change back to 
../html/html.dart included

[nweiz, 2011-10-27 22:36:54]

I've removed the ../html/html.dart stuff and fixed up the few uses of
init*Event.

http://codereview.chromium.org/8416010/diff/1004/client/layout/layout.dart
File client/layout/layout.dart (right):

http://codereview.chromium.org/8416010/diff/1004/client/layout/layout.dart#ne...
client/layout/layout.dart:8: #import('../html/html.dart');
On 2011/10/27 21:35:43, jacobr wrote:
> you accidentally uploaded with the change back to 
> ../html/html.dart included

Whoops, fixed.