Restore bottom bar on ruler.
Restore bottom bar on ruler.

The bar was accidentally removed when cleaning up the drawable-container. This
restores the bar by always drawing it in the canvas.  We draw, potentially,
twice, once for the ruler and once for the measurements bar.

BUG=trace-viewer:321
R=egraether@chromium.org

Review URL: https://codereview.appspot.com/11516043

git-svn-id: 3a56fcae908c7e16d23cb53443ea4795ac387cf2@766 0e6d7f2b-9903-5b78-7403-59d27f066143

bpsinc-native/src_third_party_trace-viewer,bpsinc-native/src_third_party_trace-viewer,bpsinc-native/src_third_party_trace-viewer,bpsinc-native/src_third_party_trace-viewer