Perform layout when adding or removing custom scrollbars

Changing existence of scrollbars should trigger a layout if non-overlay
scrollbars are used. The function FrameView::scrollbarExistenceDidChange
was only checking if the native scrollbar theme used overlay scrollbars,
without checking if the FrameView in question would actually use the
native scrollbar theme.

A consequence of this was that there would be no layout when removing
scrollbars, resulting in a contents area that was smaller than the
visible area. This the overhang linen texture to be visible at the
borders where the scrollbar should be.

Additionally, the rubberbanding math computes the stretch of the
rubberband as the overhang area, which gets messed up when the contents
area is smaller than the visible area, resulting in bizarre shuddering
behavior.

BUG=269692

Review URL: https://codereview.chromium.org/114673005

git-svn-id: svn://svn.chromium.org/blink/trunk@164352 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make MarkupAccumulator non-copyable.

BUG=

Review URL: https://codereview.chromium.org/116283003

git-svn-id: svn://svn.chromium.org/blink/trunk@164353 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove obsolete code in PopupListBox for handling Autofill popup menu rendering.

BUG=330077
TEST=<select> menus continue to render correctly
R=tkent@chromium.org

Review URL: https://codereview.chromium.org/119733003

git-svn-id: svn://svn.chromium.org/blink/trunk@164354 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move non parser-related code out of CSSParser.*

The goal here is to reduce the nubmer of CSSParser.h
includes as I'm about to introduce a replacement
CSSParser and want to be able to expose the minimal
API when doing so.

Most files include CSSParser.h either for these quote*
functions for for the cssPropertyId(String) lookup
functions (which I'll move in the next patch).

I also discovered that CSSParser.h was including
UseCounter.h even though it didn't need to
as well as that CSSParserIdioms was missing an
include for UChar.

Also removed the executable bit from several source
files in the css/ directory.

TBR=abarth
BUG=330389

Review URL: https://codereview.chromium.org/121633002

git-svn-id: svn://svn.chromium.org/blink/trunk@164355 bbb929c8-8fbe-4397-9dbb-9b2b20218538