Web Animations: Avoid player updates when compositor start time is set

Player updates were being forced following start time updates, this could cause
invalid lifecycle changes in some cases. By setting the player outdated this
can be avoided.

BUG=364250

Review URL: https://codereview.chromium.org/238353013

git-svn-id: svn://svn.chromium.org/blink/trunk@171839 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove some dead code from AXObjectCache

Remove some dead code from AXObjectCache. The textMarkerDataForVisiblePosition()
and visiblePositionForTextMarkerData() are defined but never used.

Review URL: https://codereview.chromium.org/238723010

git-svn-id: svn://svn.chromium.org/blink/trunk@171841 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations: Retire StringKeyframe setPropertyCSSValue declaration

This method was declared but never defined or called.

R=alancutter

Review URL: https://codereview.chromium.org/240003007

git-svn-id: svn://svn.chromium.org/blink/trunk@171842 bbb929c8-8fbe-4397-9dbb-9b2b20218538
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

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=171701

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

git-svn-id: svn://svn.chromium.org/blink/trunk@171843 bbb929c8-8fbe-4397-9dbb-9b2b20218538