Tweak the public/protected/private sections of MediaControls

After the merge this looked rather strange, so keep as public that
which is used by HTMLMediaElement or MediaControlElements, make
protected that which is used/overridden by MediaControlsAndroid, and
make everything else private.

BUG=341813

Review URL: https://codereview.chromium.org/143703007

git-svn-id: svn://svn.chromium.org/blink/trunk@166911 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations: FillMode Auto

Auto is equivalent to Both, except if the timed item is an Animation.
When the timed item is an Animation, Auto is equivalent to None.

See sections 6.4.1 and 6.5.2 of the Web Animations spec.

BUG=

Review URL: https://codereview.chromium.org/152423002

git-svn-id: svn://svn.chromium.org/blink/trunk@166912 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Move class filter to the heap snapshot toolbar

R=loislo@chromium.org

Review URL: https://codereview.chromium.org/143623005

git-svn-id: svn://svn.chromium.org/blink/trunk@166913 bbb929c8-8fbe-4397-9dbb-9b2b20218538