IntersectionObserver: remove gc-timing-revealing execeptions.

third_party/WebKit/Source/core/dom/IntersectionObserver.h

 // 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.
 
 #ifndef IntersectionObserver_h
 #define IntersectionObserver_h
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/dom/IntersectionObservation.h"
@@ skipping 69 matching lines @@
   Document& trackingDocument() const;
 
   const Length& topMargin() const { return m_topMargin; }
   const Length& rightMargin() const { return m_rightMargin; }
   const Length& bottomMargin() const { return m_bottomMargin; }
   const Length& leftMargin() const { return m_leftMargin; }
   void computeIntersectionObservations();
   void enqueueIntersectionObserverEntry(IntersectionObserverEntry&);
   unsigned firstThresholdGreaterThan(float ratio) const;
   void deliver();
-  void removeObservation(IntersectionObservation&);
   bool hasEntries() const { return m_entries.size(); }
   const HeapLinkedHashSet<WeakMember<IntersectionObservation>>& observations()
       const {
     return m_observations;
   }
 
   // Set the assumed initial state of the observed element. Note that this can
   // only be set before calling observe().
   // TODO(skyostil): Move this setting to IntersectionObserverInit once the API
   // is finalized.
@@ skipping 22 matching lines @@
   Length m_bottomMargin;
   Length m_leftMargin;
   unsigned m_rootIsImplicit : 1;
   // m_initialState contains values from enum InitialState
   unsigned m_initialState : 1;
 };
 
 }  // namespace blink
 
 #endif  // IntersectionObserver_h