Remove call to setMayNeedPaintInvalidation in RenderLayer::updateLayerPositionRecursive

The call to setMayNeedPaintInvalidation was compensating for a bug in RenderBox::clippedOverflowRectForPaintInvalidation.
Previously, that code considered only whether the current RenderLayer had visible
contents instead of asking whether any descendant was visible.  This change will
cause us to issue more invalidations in cases where some parts of the subtree are
visible, but they'll be the same ones we issue in the normal case when elements
are visible.

Removing this call will let us remove the RenderGeometryMap in
updateLayerPositionsAfterLayout because it's now almost entirely unused.

R=esprehn@chromium.org
BUG=383636

Review URL: https://codereview.chromium.org/337593002

git-svn-id: svn://svn.chromium.org/blink/trunk@176060 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add WTF_EXPORT to BitVector::OutOfLineBits

dllexport/dllimport aren't inherited by nested classes like visibility
attributes are on Posix, and this class has some non-inline methods that
need to get exported.

For example, if ~BitVector gets inlined, we might try calling
OutOfLineBits::destroy across a dll boundry.

BUG=82385
TEST=attempt to build blink_web.dll with Clang on Windows

Review URL: https://codereview.chromium.org/338463002

git-svn-id: svn://svn.chromium.org/blink/trunk@176061 bbb929c8-8fbe-4397-9dbb-9b2b20218538