TimelinePanel: do not scroll out grid header element in TimelineView.

BUG=
R=pfeldman@chromium.org

Review URL: https://codereview.chromium.org/166893002

git-svn-id: svn://svn.chromium.org/blink/trunk@167233 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations API: Implement setters for properties of TimedItemTiming

NOTRY=true
BUG=334927,257235

Review URL: https://codereview.chromium.org/148293021

git-svn-id: svn://svn.chromium.org/blink/trunk@167234 bbb929c8-8fbe-4397-9dbb-9b2b20218538
TimelinePanel: clear button doesn't clear overview panel in Frames and FlameChart modes.

We had no guarantees that framesModel gets RecordsCleared event earlier than views that use it.
Looks like direct call is more straightforward solution.

BUG=
R=pfeldman@chromium.org

Review URL: https://codereview.chromium.org/164753007

git-svn-id: svn://svn.chromium.org/blink/trunk@167235 bbb929c8-8fbe-4397-9dbb-9b2b20218538