Turn firstPaint and firstContentfulPaint into instant trace events

third_party/WebKit/Source/core/paint/PaintTiming.cpp

 // Copyright 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.
 
 #include "core/paint/PaintTiming.h"
 
 #include "core/dom/Document.h"
 #include "core/loader/DocumentLoader.h"
 #include "platform/TraceEvent.h"
 #include "wtf/RawPtr.h"
@@ skipping 31 matching lines @@
 {
     if (m_document && m_document->loader())
         m_document->loader()->didChangePerformanceTiming();
 }
 
 void PaintTiming::markFirstPaint()
 {
     if (m_firstPaint != 0.0)
         return;
     m_firstPaint = monotonicallyIncreasingTime();
-    TRACE_EVENT_MARK_WITH_TIMESTAMP1("blink.user_timing", "firstPaint", m_firstPaint, "frame", frame());
+    TRACE_EVENT_INSTANT1("blink.user_timing", "firstPaint", TRACE_EVENT_SCOPE_PROCESS, "frame", frame());
     notifyPaintTimingChanged();
 }
 
 void PaintTiming::markFirstTextPaint()
 {
     if (m_firstTextPaint != 0.0)
         return;
     m_firstTextPaint = monotonicallyIncreasingTime();
     TRACE_EVENT_MARK_WITH_TIMESTAMP1("blink.user_timing", "firstTextPaint", m_firstTextPaint, "frame", frame());
 
@@ skipping 14 matching lines @@
         markFirstContentfulPaint();
     else
         notifyPaintTimingChanged();
 }
 
 void PaintTiming::markFirstContentfulPaint()
 {
     if (m_firstContentfulPaint != 0.0)
         return;
     m_firstContentfulPaint = monotonicallyIncreasingTime();
-    TRACE_EVENT_MARK_WITH_TIMESTAMP1("blink.user_timing", "firstContentfulPaint", m_firstContentfulPaint, "frame", frame());
+    TRACE_EVENT_INSTANT1("blink.user_timing", "firstContentfulPaint", TRACE_EVENT_SCOPE_PROCESS, "frame", frame());
     notifyPaintTimingChanged();
 }
 
 } // namespace blink