Stack guards are too conservative
https://bugs.webkit.org/show_bug.cgi?id=115147

Reviewed by Geoffrey Garen.

Reduce the limits and simplify the decision making.

* interpreter/Interpreter.cpp:
(JSC::Interpreter::StackPolicy::StackPolicy):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149136 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[BlackBerry] Make scroll position adjustment work with pages with fixed position elements.
https://bugs.webkit.org/show_bug.cgi?id=115178

Patch by Iris Wu <shuwu@blackberry.com> on 2013-04-25
Reviewed by Rob Buis.

PR 308796

Currently the position WebPage::adjustDocumentScrollPosition adjusts is the top
left point of the viewport.
On the page with fixed position elements, we want it to adjust the position beneath
the fixed elements so it can be always visible.

The basic idea is:
1.  Detect if there are fixed position elements before going through ProximityDetector.
2.  If the fixed element exists, calculate its the size and the actual visible position
    beneath it.
3.  Pass the position to ProximityDetector. Then according to the new position we get,
    calculate the top left position of the viewport (final scroll position).

* Api/WebPage.cpp:
(BlackBerry::WebKit::WebPage::fixedElementSizeDelta):
(WebKit):
* Api/WebPage.h:
* Api/WebPageCompositor.cpp:
(BlackBerry::WebKit::WebPageCompositorPrivate::findFixedElementRect):
(WebKit):
* Api/WebPageCompositor_p.h:
(WebPageCompositorPrivate):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149137 268f45cc-cd09-0410-ab3c-d52691b4dbfc