Implement Composition.buildFromEvents()

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/line_chart.css',
       'tracing/ui/base/list_view.css',
       'tracing/ui/base/pie_chart.css',
@@ skipping 449 matching lines @@
       'tracing/value/diagnostics/generic.html',
       'tracing/value/diagnostics/iteration_info.html',
       'tracing/value/diagnostics/related_event_set.html',
       'tracing/value/diagnostics/related_value_map.html',
       'tracing/value/diagnostics/related_value_set.html',
       'tracing/value/generic_table.html',
       'tracing/value/numeric.html',
       'tracing/value/time_display_mode.html',
       'tracing/value/ui/all_value_set_views.html',
       'tracing/value/ui/array_of_numbers_span.html',
+      'tracing/value/ui/composition_span.html',
       'tracing/value/ui/diagnostic_span.html',
       'tracing/value/ui/generic_diagnostic_span.html',
       'tracing/value/ui/generic_table_view.html',
       'tracing/value/ui/histogram_span.html',
       'tracing/value/ui/iteration_info_span.html',
       'tracing/value/ui/numeric_stats_span.html',
       'tracing/value/ui/preferred_display_unit.html',
       'tracing/value/ui/related_event_set_span.html',
       'tracing/value/ui/related_value_map_span.html',
       'tracing/value/ui/related_value_set_span.html',
@@ skipping 13 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)',
     ],
   }
 }