Web Animations: Remove legacy animations engine.

BUG=334225

Review URL: https://codereview.chromium.org/139273007

git-svn-id: svn://svn.chromium.org/blink/trunk@166881 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Clean up dead code related to PopupContainer

The only type of PopupContainer created is PopupContainer::Select, so
there's no need for storing that type anywhere.

Also remove an always-false second argument from PopupContainer::popupOpened.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/159233003

git-svn-id: svn://svn.chromium.org/blink/trunk@166882 bbb929c8-8fbe-4397-9dbb-9b2b20218538
CSS Parser: Fix use after free resulting from CSSParserValueList::extend()

CSSParserValueLists can contain pointers and are responsible for freeing
them in their destructor.
This patch prevents sharing of pointers between different
CSSParserValueLists to avoid multiple frees of shared pointers. This is
achieved by changing extend() to stealValues() so items are moved between
lists instead of copied.

BUG=340001
R=eseidel@chromium.org, mikelawther@chromium.org

Review URL: https://codereview.chromium.org/157363004

git-svn-id: svn://svn.chromium.org/blink/trunk@166883 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Hardcode the UseCounter enum values so that we don't get off-by-one errors when an enum value is deleted.

After this patch, we can also get rid of all the REMOVED* enum values.

Review URL: https://codereview.chromium.org/159263003

git-svn-id: svn://svn.chromium.org/blink/trunk@166884 bbb929c8-8fbe-4397-9dbb-9b2b20218538