Refactor IntersectionGeometry class and move it to core/layout.

third_party/WebKit/Source/core/dom/IntersectionObservation.cpp

 // Copyright 2016 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/dom/IntersectionObservation.h"
 
 #include "core/dom/ElementRareData.h"
 #include "core/dom/IntersectionObserver.h"
+#include "core/layout/IntersectionGeometry.h"
 
 namespace blink {
 
-IntersectionObservation::IntersectionObservation(
-    IntersectionObserver& observer,
-    Element& target,
-    IntersectionGeometry::ReportRootBounds shouldReportRootBounds)
+IntersectionObservation::IntersectionObservation(IntersectionObserver& observer,
+                                                 Element& target,
+                                                 bool shouldReportRootBounds)
     : m_observer(observer),
       m_target(&target),
-      m_shouldReportRootBounds(
-          shouldReportRootBounds ==
-          IntersectionGeometry::ReportRootBounds::kShouldReportRootBounds),
+      m_shouldReportRootBounds(shouldReportRootBounds),
       m_lastThresholdIndex(0) {}
 
 void IntersectionObservation::computeIntersectionObservations(
     DOMHighResTimeStamp timestamp) {
   if (!m_target)
     return;
   Vector<Length> rootMargin(4);
   rootMargin[0] = m_observer->topMargin();
   rootMargin[1] = m_observer->rightMargin();
   rootMargin[2] = m_observer->bottomMargin();
   rootMargin[3] = m_observer->leftMargin();
+  Node* rootNode = m_observer->rootNode();
   IntersectionGeometry geometry(
-      m_observer->rootNode(), target(), rootMargin,
-      m_shouldReportRootBounds
-          ? IntersectionGeometry::ReportRootBounds::kShouldReportRootBounds
-          : IntersectionGeometry::ReportRootBounds::kShouldNotReportRootBounds);
+      rootNode && !rootNode->isDocumentNode() ? toElement(rootNode) : nullptr,
+      *target(), rootMargin, m_shouldReportRootBounds);
   geometry.computeGeometry();
 
   // Some corner cases for threshold index:
   //   - If target rect is zero area, because it has zero width and/or zero
   //     height,
   //     only two states are recognized:
   //     - 0 means not intersecting.
   //     - 1 means intersecting.
   //     No other threshold crossings are possible.
   //   - Otherwise:
@@ skipping 40 matching lines @@
     target()->ensureIntersectionObserverData().removeObservation(observer());
   m_observer.clear();
 }
 
 DEFINE_TRACE(IntersectionObservation) {
   visitor->trace(m_observer);
   visitor->trace(m_target);
 }
 
 }  // namespace blink