Make GPU-rasterized layers more visible in frame viewer
Make GPU-rasterized layers more visible in frame viewer

This makes GPU-rasterized layers have a thicker border, and also scales
border width by the device pixel ratio.

BUG=chromium:353130
R=nduca@chromium.org

Review URL: https://codereview.appspot.com/81460044

git-svn-id: 3a56fcae908c7e16d23cb53443ea4795ac387cf2@1214 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