Get rid of unnecessary weak pointer cleanup.

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/frame/FrameView.h"
 #include "core/layout/LayoutBox.h"
 #include "core/layout/LayoutText.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/PaintLayer.h"
 
 namespace blink {
 
 IntersectionObservation::IntersectionObservation(IntersectionObserver& observer, Element& target, bool shouldReportRootBounds)
     : m_observer(observer)
     , m_target(target.ensureIntersectionObserverData().createWeakPtr(&target))
     , m_active(true)
     , m_shouldReportRootBounds(shouldReportRootBounds)
     , m_lastThresholdIndex(0)
 {
 }
 
 void IntersectionObservation::initializeGeometry(IntersectionGeometry& geometry)
 {
+    ASSERT(m_target);
     LayoutObject* targetLayoutObject = m_target->layoutObject();
     if (targetLayoutObject->isBoxModelObject())
         geometry.targetRect = toLayoutBoxModelObject(targetLayoutObject)->visualOverflowRect();
     else
         geometry.targetRect = toLayoutText(targetLayoutObject)->visualOverflowRect();
     geometry.intersectionRect = geometry.targetRect;
 }
 
 void IntersectionObservation::clipToRoot(LayoutRect& rect)
 {
     // Map and clip rect into root element coordinates.
     // TODO(szager): the writing mode flipping needs a test.
+    ASSERT(m_target);
     LayoutObject* rootLayoutObject = m_observer->rootLayoutObject();
     LayoutObject* targetLayoutObject = m_target->layoutObject();
     targetLayoutObject->mapToVisibleRectInAncestorSpace(toLayoutBoxModelObject(rootLayoutObject), rect, nullptr);
     if (rootLayoutObject->hasOverflowClip()) {
         LayoutBox* rootLayoutBox = toLayoutBox(rootLayoutObject);
         LayoutRect clipRect(LayoutPoint(), LayoutSize(rootLayoutBox->layer()->size()));
         rootLayoutBox->flipForWritingMode(rect);
         rect.intersect(clipRect);
         rootLayoutBox->flipForWritingMode(rect);
     }
@@ skipping 19 matching lines @@
     geometry.rootRect.moveBy(-scrollPosition);
 }
 
 static void mapRectToDocumentCoordinates(LayoutObject& layoutObject, LayoutRect& rect)
 {
     rect = LayoutRect(layoutObject.localToAbsoluteQuad(FloatQuad(FloatRect(rect)), UseTransforms | ApplyContainerFlip | TraverseDocumentBoundaries).boundingBox());
 }
 
 bool IntersectionObservation::computeGeometry(IntersectionGeometry& geometry)
 {
+    ASSERT(m_target);
     LayoutObject* rootLayoutObject = m_observer->rootLayoutObject();
     LayoutObject* targetLayoutObject = m_target->layoutObject();
     if (!rootLayoutObject->isBoxModelObject())
         return false;
     if (!targetLayoutObject->isBoxModelObject() && !targetLayoutObject->isText())
         return false;
 
     // Initialize targetRect and intersectionRect to bounds of target, in target's coordinate space.
     initializeGeometry(geometry);
 
@@ skipping 49 matching lines @@
             pixelSnappedIntRect(geometry.rootRect),
             pixelSnappedIntRect(geometry.intersectionRect),
             targetElement);
         observer().enqueueIntersectionObserverEntry(*newEntry);
     }
     setLastThresholdIndex(newThresholdIndex);
 }
 
 void IntersectionObservation::disconnect()
 {
-    if (m_target) {
+    if (m_target)
         m_target->ensureIntersectionObserverData().removeObservation(this->observer());
-        m_target.clear();
-    }
     m_observer->removeObservation(*this);
     m_observer.clear();
 }
 
 DEFINE_TRACE(IntersectionObservation)
 {
     visitor->trace(m_observer);
     visitor->trace(m_target);
 }
 
 } // namespace blink