[BlackBerry] Don't use WebKit thread scale information in WebPageCompositor.
https://bugs.webkit.org/show_bug.cgi?id=113447
Internal PR 313452

Patch by Jakob Petsovits <jpetsovits@blackberry.com> on 2013-03-28
Reviewed by Rob Buis.

Potential threading problems are avoided by moving from
WebPage members and mapToTransformed() to the web page
client's userInterfaceViewportAccessor().

As part of this cleaning effort, the WebPageCompositor's
render() method is changed to now take document instead of
pixel coordinates.

* Api/BackingStore.cpp:
(BlackBerry::WebKit::BackingStorePrivate::compositeContents):
* Api/WebPageCompositor.cpp:
(BlackBerry::WebKit::WebPageCompositorPrivate::render):
(BlackBerry::WebKit::WebPageCompositor::render):
* Api/WebPageCompositor.h:
* Api/WebPageCompositor_p.h:
(WebPageCompositorPrivate):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147136 268f45cc-cd09-0410-ab3c-d52691b4dbfc