Out-of-view fixed position check should not be affected by page scale at all on Mac
https://bugs.webkit.org/show_bug.cgi?id=110294
-and corresponding-
<rdar://problem/13247582>

Reviewed by Simon Fraser.

Source/WebCore: 

Don't scale the layerBounds. Generally, the layerBounds should be relative to the 
viewBounds which are also unscaled. Chromium used to want this behavior, but it is 
covered by their pageScaleFactorAppliedInCompositor implementation now.

* rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::requiresCompositingForPosition):

LayoutTests: 

These layer results should be the same regardless of the scale factor.

* compositing/layer-creation/fixed-position-out-of-view-scaled-expected.txt:
* compositing/layer-creation/fixed-position-out-of-view-scaled-scroll-expected.txt:
* compositing/layer-creation/fixed-position-out-of-view-scaled-scroll.html:
* compositing/layer-creation/fixed-position-out-of-view-scaled.html:
* platform/chromium/compositing/layer-creation/fixed-position-out-of-view-scaled-expected.txt: Removed.
* platform/chromium/compositing/layer-creation/fixed-position-out-of-view-scaled-scroll-expected.txt: Removed.
* platform/mac-wk2/tiled-drawing/fixed/four-bars-zoomed-expected.txt:

Skip these on Chromium for now.
* platform/chromium/TestExpectations:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143641 268f45cc-cd09-0410-ab3c-d52691b4dbfc