Check that Diagnostic subclasses are registered in presubmit.

tracing/trace_viewer.gypi

Index: tracing/trace_viewer.gypi
diff --git a/tracing/trace_viewer.gypi b/tracing/trace_viewer.gypi
index af2e9ef49c508ce7cdc40b02e6cdcb323279c6a0..d94385006b1a525a27c3cd82f1e8088688c4b23f 100644
--- a/tracing/trace_viewer.gypi
+++ b/tracing/trace_viewer.gypi
@@ -520,6 +520,7 @@
       'tracing/ui/tracks/x_axis_track.html',
       'tracing/ui/view_specific_brushing_state.html',
       'tracing/value/csv_builder.html',
+      'tracing/value/diagnostics/all_diagnostics.html',
       'tracing/value/diagnostics/breakdown.html',
       'tracing/value/diagnostics/buildbot_info.html',
       'tracing/value/diagnostics/collected_generic.html',
@@ -536,6 +537,7 @@
       'tracing/value/diagnostics/merged_device_info.html',
       'tracing/value/diagnostics/merged_revision_info.html',
       'tracing/value/diagnostics/merged_telemetry_info.html',
+      'tracing/value/diagnostics/ownership.html',
       'tracing/value/diagnostics/related_event_set.html',
       'tracing/value/diagnostics/related_histogram_breakdown.html',
       'tracing/value/diagnostics/related_histogram_map.html',