Remove use of filter property for CSS opacity

Was used for IE8 support, no longer needed.

Change-Id: I1e7a1e676022dd7607c808bd44848cbf22a9e958
Prevent visual effect on disabled toolbar buttons

Bug: 33113
Change-Id: Icbf9ac6cff5e3f914268fe14d1b430609dedd49e
Merge changes Icbf9ac6c,I1e7a1e67

* changes:
  Prevent visual effect on disabled toolbar buttons
  Remove use of filter property for CSS opacity