Statistics of LayoutBox rare data reasons

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

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 6e8030fca4ea558c1c7cc5a6ddd66c0f999ffc1b..10e38a4e9195a4174cea9e0f2528061a7501ce06 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -2990,6 +2990,36 @@ void FrameView::clearPrintContext() {
   m_printContext.clear();
 }
 
+static int gFrameCounts[7];
+int* frameCounts() {
+  return gFrameCounts;
+}
+
+static void countFrames(const Frame& frame) {
+  gFrameCounts[0]++;
+  for (Frame* child = frame.tree().firstChild(); child;
+       child = child->tree().nextSibling()) {
+    if (!child->isLocalFrame()) {
+      gFrameCounts[1]++;
+      continue;
+    }
+    if (!child->ownerLayoutObject())
+      gFrameCounts[2]++;
+    if (FrameView* childView = toLocalFrame(child)->view()) {
+      if (childView->shouldThrottleRendering()) {
+        gFrameCounts[3]++;
+        if (!child->ownerLayoutObject())
+          gFrameCounts[4]++;
+      }
+      if (!childView->layoutView())
+        gFrameCounts[5]++;
+    } else {
+      gFrameCounts[6]++;
+    }
+    countFrames(*child);
+  }
+}
+
 // TODO(leviw): We don't assert lifecycle information from documents in child
 // PluginViews.
 void FrameView::updateLifecyclePhasesInternal(
@@ -3121,6 +3151,10 @@ void FrameView::updateLifecyclePhasesInternal(
   }
 
   updateViewportIntersectionsForSubtree(targetState);
+
+  gFrameCounts[0] = gFrameCounts[1] = gFrameCounts[2] = gFrameCounts[3] =
+      gFrameCounts[4] = 0;
+  countFrames(*m_frame);
 }
 
 void FrameView::enqueueScrollAnchoringAdjustment(