A sizes attribute parser

This CL implements a parser for HTMLImageElement's sizes attribute.
It also hooks that parser to HTMLImageElement, but doesn't yet do anything with the output.

BUG=357586

Review URL: https://codereview.chromium.org/224733011

git-svn-id: svn://svn.chromium.org/blink/trunk@171701 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rebaseline hackernews-comments.html.

BUG=332944
NOTRY=true

Review URL: https://codereview.chromium.org/235883012

git-svn-id: svn://svn.chromium.org/blink/trunk@171702 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Improve XML document UseCounters

This patch makes the XMLDocument UseCounter useful by ignoring cases
where a frameView is not available (e.g., responseXML). This patch
also introduces SVGSVGElementInXMLDocument which counts both
SVG-as-image and SVG top-level documents, allowing us to separate
SVG XML usage from the total XMLDocument count.

Tested cases:
ajax request with responseXML[1] - XMLDocument no longer counts this
xml doc as root[2] - XMLDocument(+1)
svg doc as root[3] - XMLDocument(+1), SVGSVGElementInXMLDocument(+1)
svg doc in image[4] - XMLDocument(+1), SVGSVGElementInXMLDocument(+1)
svg inline[5] - Neither XMLDocument nor SVGSVGElementInXMLDocument

[1] http://www.w3schools.com/ajax/ajax_xmlfile.asp
[2] http://www.w3.org/Style/Examples/001/doc.xml
[3] http://pr.gg/svg.svg
[4] http://pr.gg/svg.html
[5] http://pr.gg/inline.html

BUG=361411

Review URL: https://codereview.chromium.org/235883004

git-svn-id: svn://svn.chromium.org/blink/trunk@171704 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove unused argument in RenderLayer::needsCompositingLayersRebuiltForFilters

The didPaintWithLayers argument is unused. Also added a comment to a FIXME
for future reference.

BUG=343759

Review URL: https://codereview.chromium.org/239533003

git-svn-id: svn://svn.chromium.org/blink/trunk@171705 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Use the media controls play button internal state for painting

MediaControlElement::displayType() is not actually used for rendering,
the logic is instead duplicated in RenderMediaControls, sometimes with
minor differences. When scrubbing was made internal to the controls in
r169814, I neglected to update the corresponding rendering code.

BUG=359522

Review URL: https://codereview.chromium.org/239113003

git-svn-id: svn://svn.chromium.org/blink/trunk@171706 bbb929c8-8fbe-4397-9dbb-9b2b20218538