DevTools: move non panel-specific CSS from layerPanel.css to timelinePanel.css

... so we can match the direction of code dependency (Layers panel currently
depends on Timeline panel to show shared layer views).

BUG=

Review URL: https://codereview.chromium.org/658793002

git-svn-id: svn://svn.chromium.org/blink/trunk@183758 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [Console] select property names with double click

As of today, double click on property name in ObjectPropertyTreeElement
results in editing of the property value. The patch changes the
behavior so that double click on property name just sets a selection,
and one has to double-click on property value to edit it.

BUG=423085
R=vsevik

Review URL: https://codereview.chromium.org/656123002

git-svn-id: svn://svn.chromium.org/blink/trunk@183760 bbb929c8-8fbe-4397-9dbb-9b2b20218538