DevTools: bring violations and timeline warnings in sync.

third_party/WebKit/Source/devtools/front_end/timeline/TimelineUIUtils.js

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 1720 matching lines @@
         span.appendChild(UI.createDocumentationLink(
             '../../fundamentals/performance/rendering/avoid-large-complex-layouts-and-layout-thrashing#avoid-forced-synchronous-layouts',
             Common.UIString('Forced reflow')));
         span.createTextChild(Common.UIString(' is a likely performance bottleneck.'));
         break;
       case warnings.IdleDeadlineExceeded:
         span.textContent = Common.UIString(
             'Idle callback execution extended beyond deadline by ' +
             Number.millisToString(event.duration - eventData['allottedMilliseconds'], true));
         break;
+      case warnings.LongHandler:
+        span.textContent = Common.UIString('Handler took ' + Number.millisToString(event.duration, true));

[alph, 2016/11/19 05:36:27]

May be it can be more explicit on what's wrong, e.g. 'Handler took too long ...'

[caseq, 2016/11/19 05:51:08]

Common.UIString('Handler look %s', Number.millisToString(...))

+        break;
+      case warnings.LongRecurringHandler:
+        span.textContent = Common.UIString('Recurring handler took ' + Number.millisToString(event.duration, true));

[caseq, 2016/11/19 05:51:08]

ditto.

+        break;
       case warnings.V8Deopt:
         span.appendChild(UI.createExternalLink(
             'https://github.com/GoogleChrome/devtools-docs/issues/53', Common.UIString('Not optimized')));
         span.createTextChild(Common.UIString(': %s', eventData['deoptReason']));
         break;
       default:
         console.assert(false, 'Unhandled TimelineModel.WarningType');
     }
     return span;
   }
@@ skipping 482 matching lines @@
   /**
    * @param {!SDK.TracingModel.Event} event
    * @param {string=} warningType
    */
   appendWarningRow(event, warningType) {
     var warning = Timeline.TimelineUIUtils.eventWarning(event, warningType);
     if (warning)
       this.appendElementRow(Common.UIString('Warning'), warning, true);
   }
 };