Don't trace LayoutObject geometry prior to running layout.

Source/core/layout/TracedLayoutObject.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 "config.h"
 #include "core/layout/TracedLayoutObject.h"
 
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutTableCell.h"
 #include "core/layout/LayoutText.h"
 #include "core/layout/LayoutView.h"
 #include "platform/JSONValues.h"
 
 namespace blink {
 
-PassRefPtr<TraceEvent::ConvertableToTraceFormat> TracedLayoutObject::create(const LayoutView& view)
+PassRefPtr<TraceEvent::ConvertableToTraceFormat> TracedLayoutObject::create(const LayoutView& view, bool traceGeometry)
 {
-    return adoptRef(new TracedLayoutObject(view));
+    return adoptRef(new TracedLayoutObject(view, traceGeometry));
 }
 
 String TracedLayoutObject::asTraceFormat() const
 {
     StringBuilder builder;
     RefPtr<JSONObject> json(toJSON());
     json->writeJSON(&builder);
     return builder.toString();
 }
 
-TracedLayoutObject::TracedLayoutObject(const LayoutObject& object)
+TracedLayoutObject::TracedLayoutObject(const LayoutObject& object, bool traceGeometry)
     : m_address((unsigned long) &object)
     , m_isAnonymous(object.isAnonymous())
     , m_isPositioned(object.isOutOfFlowPositioned())
     , m_isRelPositioned(object.isRelPositioned())
     , m_isStickyPositioned(object.isStickyPositioned())
     , m_isFloating(object.isFloating())
     , m_selfNeeds(object.selfNeedsLayout())
     , m_positionedMovement(object.needsPositionedMovementLayout())
     , m_childNeeds(object.normalChildNeedsLayout())
     , m_posChildNeeds(object.posChildNeedsLayout())
     , m_isTableCell(object.isTableCell())
     , m_name(String(object.name()).isolatedCopy())
-    , m_absRect(object.absoluteBoundingBoxRect())
+    , m_absRect(traceGeometry ? object.absoluteBoundingBoxRect() : IntRect())
 {
     if (Node* node = object.node()) {
         m_tag = String(node->nodeName()).isolatedCopy();
         if (node->isElementNode()) {
             Element& element = toElement(*node);
             if (element.hasID())
                 m_id = String(element.getIdAttribute()).isolatedCopy();
             if (element.hasClass()) {
                 for (size_t i = 0; i < element.classNames().size(); ++i) {
                     m_classNames.append(
                         String(element.classNames()[i]).isolatedCopy());
                 }
             }
         }
     }
 
     // FIXME: When the fixmes in LayoutTreeAsText::writeLayoutObject() are
     // fixed, deduplicate it with this.
-    if (object.isText()) {
-        m_rect = LayoutRect(toLayoutText(object).linesBoundingBox());
-    } else if (object.isLayoutInline()) {
-        m_rect = LayoutRect(toLayoutInline(object).linesBoundingBox());
-    } else if (object.isBox()) {
-        m_rect = toLayoutBox(&object)->frameRect();
+    if (traceGeometry) {
+        if (object.isText()) {
+            m_rect = LayoutRect(toLayoutText(object).linesBoundingBox());
+        } else if (object.isLayoutInline()) {
+            m_rect = LayoutRect(toLayoutInline(object).linesBoundingBox());
+        } else if (object.isBox()) {
+            m_rect = toLayoutBox(&object)->frameRect();
+        }
     }
 
     if (m_isTableCell) {
         const LayoutTableCell& c = toLayoutTableCell(object);
         if (c.row() && c.row()->rowIndexWasSet() && c.hasCol()
             && (!c.row()->section() || !c.row()->section()->needsCellRecalc())) {
             m_row = c.rowIndex();
             m_col = c.col();
             m_rowSpan = c.rowSpan();
             m_colSpan = c.colSpan();
         }
     }
 
     for (LayoutObject* child = object.slowFirstChild(); child; child = child->nextSibling()) {
-        m_children.append(adoptRef(new TracedLayoutObject(*child)));
+        m_children.append(adoptRef(new TracedLayoutObject(*child, traceGeometry)));
     }
 }
 
 PassRefPtr<JSONObject> TracedLayoutObject::toJSON() const
 {
     RefPtr<JSONObject> json(JSONObject::create());
     json->setNumber("address", m_address);
     json->setString("name", m_name);
     if (!m_tag.isEmpty())
         json->setString("tag", m_tag);
@@ skipping 42 matching lines @@
         RefPtr<JSONArray> children(JSONArray::create());
         for (const auto& child : m_children) {
             children->pushObject(child->toJSON());
         }
         json->setArray("children", children);
     }
     return json.release();
 }
 
 } // namespace blink