Define DiagnosticMap and a basic Diagnostic hierarchy

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 430 matching lines @@
       'tracing/ui/tracks/ruler_track.html',
       'tracing/ui/tracks/sample_track.html',
       'tracing/ui/tracks/slice_group_track.html',
       'tracing/ui/tracks/slice_track.html',
       'tracing/ui/tracks/spacing_track.html',
       'tracing/ui/tracks/stacked_bars_track.html',
       'tracing/ui/tracks/thread_track.html',
       'tracing/ui/tracks/track.html',
       'tracing/ui/value_set_view.html',
       'tracing/ui/view_specific_brushing_state.html',
+      'tracing/value/diagnostics/composition.html',
+      'tracing/value/diagnostics/diagnostic.html',
+      'tracing/value/diagnostics/diagnostic_map.html',
+      'tracing/value/diagnostics/generic.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/array_of_numbers_span.html',
       'tracing/value/ui/generic_table_view.html',
       'tracing/value/ui/preferred_display_unit.html',
       'tracing/value/ui/scalar_span.html',
       'tracing/value/unit.html',
       'tracing/value/value.html',
     ],
     'tracing_img_files': [
       'tracing/ui/extras/chrome/cc/images/input-event.png',
       'tracing/ui/extras/chrome/gpu/images/checkerboard.png',
       'tracing/ui/images/chrome-left.png',
       'tracing/ui/images/chrome-mid.png',
       'tracing/ui/images/chrome-right.png',
       'tracing/ui/images/ui-states.png',
     ],
     'tracing_files': [
       '<@(tracing_css_files)',
       '<@(tracing_js_html_files)',
       '<@(tracing_img_files)',
     ],
   }
 }