Add frame ID to LayoutAnalyzer trace event

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 821 matching lines @@
         m_analyzer = adoptPtr(new LayoutAnalyzer());
     m_analyzer->reset();
 }
 
 PassOwnPtr<TracedValue> FrameView::analyzerCounters()
 {
     if (!m_analyzer)
         return TracedValue::create();
     OwnPtr<TracedValue> value = m_analyzer->toTracedValue();
     value->setString("host", layoutView()->document().location()->host());
+    value->setString("frame", String::format("0x%" PRIx64, static_cast<uint64_t>(reinterpret_cast<intptr_t>(m_frame.get()))));

[benjhayden, 2016/04/27 16:36:06]

Yeah, sorry this is super non-obvious, but I'm told that the correct way to
stringify pointers is like this:
value->setString("frame", String::format("%" PRIxPTR,
reinterpret_cast<uintptr_t>(m_frame.get())));

[Kunihiko Sakamoto, 2016/04/28 02:56:06]

Thanks for the tip, done.
Let me keep the "0x" prefix for consistency with other trace events.

[benjhayden, 2016/04/28 04:22:10]

Doesn't the PRIxPTR already generate the 0x prefix?

[Kunihiko Sakamoto, 2016/04/28 04:47:23]

No, on my Linux box, PRIxPTR is expanded to "lx" so 0x is not prepended.

     return value.release();
 }
 
 #define PERFORM_LAYOUT_TRACE_CATEGORIES "blink,benchmark," TRACE_DISABLED_BY_DEFAULT("blink.debug.layout")
 
 void FrameView::performLayout(bool inSubtreeLayout)
 {
     ASSERT(inSubtreeLayout || m_layoutSubtreeRootList.isEmpty());
 
     TRACE_EVENT_BEGIN0(PERFORM_LAYOUT_TRACE_CATEGORIES, "FrameView::performLayout");
@@ skipping 3216 matching lines @@
     return m_hiddenForThrottling && m_crossOriginForThrottling;
 }
 
 LayoutBox& FrameView::boxForScrollControlPaintInvalidation() const
 {
     ASSERT(layoutView());
     return *layoutView();
 }
 
 } // namespace blink