Don't trace LayoutObject geometry prior to running layout.

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index ce13be3f76d82bfe61c411e7666bcdeca3b0c139..ee564f6dc83a15f65eff20330f06bd9d3c7154a9 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -1023,13 +1023,10 @@ void FrameView::layout()
         }
 
         TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(TRACE_DISABLED_BY_DEFAULT("blink.debug.layout"), "LayoutTree",
-            this, TracedLayoutObject::create(*layoutView()));
+            this, TracedLayoutObject::create(*layoutView(), false));
 
         performLayout(inSubtreeLayout);
 
-        TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(TRACE_DISABLED_BY_DEFAULT("blink.debug.layout"), "LayoutTree",
-            this, TracedLayoutObject::create(*layoutView()));
-
         ASSERT(m_layoutSubtreeRootList.isEmpty());
     } // Reset m_layoutSchedulingEnabled to its previous value.
 
@@ -1041,6 +1038,9 @@ void FrameView::layout()
     // FIXME: Could find the common ancestor layer of all dirty subtrees and mark from there. crbug.com/462719
     layoutView()->enclosingLayer()->updateLayerPositionsAfterLayout();
 
+    TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(TRACE_DISABLED_BY_DEFAULT("blink.debug.layout"), "LayoutTree",

[szager1, 2015/09/03 22:34:41]

Moving this after updateLayerPositionsAfterLayout() is necessary to avoid the
crash mentioned in the bug.

+        this, TracedLayoutObject::create(*layoutView(), true));
+
     layoutView()->compositor()->didLayout();
 
     m_layoutCount++;