Re-enabled coverage rects.
Re-enabled coverage rects.

This patch enables coverage rects again, since I think it works
properly for high-dpi now.

BUG=none
R=nduca@chromium.org

Review URL: https://codereview.appspot.com/13368055

git-svn-id: 3a56fcae908c7e16d23cb53443ea4795ac387cf2@1004 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