Refactor diagnostic spans to share a polymer behavior.

tracing/trace_viewer.gypi

 # Copyright (c) 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
     'tracing_css_files': [
       'tracing/ui/base/list_view.css',
       'tracing/ui/extras/about_tracing/common.css',
       'tracing/ui/extras/chrome/cc/display_item_list_view.css',
@@ skipping 544 matching lines @@
       'tracing/value/histogram_grouping.html',
       'tracing/value/histogram_parameter_collector.html',
       'tracing/value/histogram_set.html',
       'tracing/value/histogram_set_hierarchy.html',
       'tracing/value/ui/breakdown_span.html',
       'tracing/value/ui/buildbot_info_span.html',
       'tracing/value/ui/collected_related_event_set_span.html',
       'tracing/value/ui/date_range_span.html',
       'tracing/value/ui/diagnostic_map_table.html',
       'tracing/value/ui/diagnostic_span.html',
+      'tracing/value/ui/diagnostic_span_behavior.html',
       'tracing/value/ui/generic_set_span.html',
       'tracing/value/ui/histogram_set_controls.html',
       'tracing/value/ui/histogram_set_table.html',
       'tracing/value/ui/histogram_set_table_cell.html',
       'tracing/value/ui/histogram_set_table_name_cell.html',
       'tracing/value/ui/histogram_set_table_row.html',
       'tracing/value/ui/histogram_set_view.html',
       'tracing/value/ui/histogram_set_view_state.html',
       'tracing/value/ui/histogram_span.html',
       'tracing/value/ui/merged_buildbot_info_span.html',
@@ skipping 18 matching lines @@
       'tracing/ui/images/chrome-right.png',
       'tracing/ui/images/ui-states.png',
     ],
     'tracing_files': [
       '<@(tracing_css_files)',
       '<@(tracing_js_html_files)',
       '<@(tracing_img_files)',
     ],
   }
 }