Adjust the size of the bubble to the size of its content in Safari

Safari doesn't adjust the size of the popover automatically to the size of its content. So currently the size of the bubble is hard-coded in metadata.safari, and when you collapse the ad counter the bubble will have a large empty area. However it is possible to change the size of the bubble programatically. So I have added a listener for DOMSubtreeModified that adjust the size of the bubble to its content.

[Wladimir Palant, 2014-01-15 15:47:13]

LGTM but please answer my answer below.

http://codereview.adblockplus.org/6476185965953024/diff/5629499534213120/safa...
File safari/ext/popup.js (right):

http://codereview.adblockplus.org/6476185965953024/diff/5629499534213120/safa...
safari/ext/popup.js:31: safari.self.height = document.body.offsetHeight;
What about document.documentElement.offsetWidth/Height, doesn't it have the
right value? IMHO that should be used here.

[Sebastian Noack, 2014-01-15 17:21:45]

I also did following changes:

* Used WebkitMutationObserver when available. The DOMSubtreeModified event isn't
only deprecated, but also buggy in newer versions of Safari.
* The popup is resized onload for the first time.
  * That way the size is also adjusted when resources like images without given
dimensions are loaded.
  * And we don't resize the popup multiple times while the DOM is constructed,
anymore.

[Sebastian Noack, 2014-01-15 17:21:52]

http://codereview.adblockplus.org/6476185965953024/diff/5629499534213120/safa...
File safari/ext/popup.js (right):

http://codereview.adblockplus.org/6476185965953024/diff/5629499534213120/safa...
safari/ext/popup.js:31: safari.self.height = document.body.offsetHeight;
On 2014/01/15 15:47:13, Wladimir Palant wrote:
> What about document.documentElement.offsetWidth/Height, doesn't it have the
> right value? IMHO that should be used here.

No, it doesn't has the right value (sometimes?). Don't know whether we have the
wrong expectations or whether it is a Safari bug. But document.body works fine.

[Wladimir Palant, 2014-01-16 07:55:59]

http://codereview.adblockplus.org/6476185965953024/diff/5724160613416960/safa...
File safari/ext/popup.js (right):

http://codereview.adblockplus.org/6476185965953024/diff/5724160613416960/safa...
safari/ext/popup.js:27: if ("WebKitMutationObserver" in window)
We should go for the standardized name first, future Safari versions should
support it. Maybe like this:

    if ("MutationObserver" in window || "WebKitMutationObserver" in window)
    {
      var observer = new (window.MutationObserver
|| window.WebKitMutationObserver)(updateSize);
      ...

Style nit: please put curly brackets around multiline blocks even if they
consist of only one statement - readability suffers otherwise.

[Sebastian Noack, 2014-01-16 11:00:31]

http://codereview.adblockplus.org/6476185965953024/diff/5724160613416960/safa...
File safari/ext/popup.js (right):

http://codereview.adblockplus.org/6476185965953024/diff/5724160613416960/safa...
safari/ext/popup.js:27: if ("WebKitMutationObserver" in window)
On 2014/01/16 07:55:59, Wladimir Palant wrote:
> We should go for the standardized name first, future Safari versions should
> support it. Maybe like this:
> 
>     if ("MutationObserver" in window || "WebKitMutationObserver" in window)
>     {
>       var observer = new (window.MutationObserver
> || window.WebKitMutationObserver)(updateSize);
>       ...
> 
> Style nit: please put curly brackets around multiline blocks even if they
> consist of only one statement - readability suffers otherwise.

Done.