IntersectionObserver: make exceptions match spec

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

Index: third_party/WebKit/Source/core/dom/IntersectionObserver.h
diff --git a/third_party/WebKit/Source/core/dom/IntersectionObserver.h b/third_party/WebKit/Source/core/dom/IntersectionObserver.h
index 12b82835d8efc1c557b4e9085d9290a859000383..c027b3cff9c7422bdc70fc7fe8389f6b475d7b96 100644
--- a/third_party/WebKit/Source/core/dom/IntersectionObserver.h
+++ b/third_party/WebKit/Source/core/dom/IntersectionObserver.h
@@ -29,8 +29,9 @@ public:
     static void resumeSuspendedObservers();
 
     // API methods
-    void observe(Element*, ExceptionState&);
-    void unobserve(Element*, ExceptionState&);
+    void observe(Element*);
+    void unobserve(Element*);
+    void disconnect();
     HeapVector<Member<IntersectionObserverEntry>> takeRecords();
     Element* root() const;
     String rootMargin() const;
@@ -38,7 +39,6 @@ public:
 
     Node* rootNode() const { return m_root.get(); }
     LayoutObject* rootLayoutObject() const;
-    bool hasPercentMargin() const;
     const Length& topMargin() const { return m_topMargin; }
     const Length& rightMargin() const { return m_rightMargin; }
     const Length& bottomMargin() const { return m_bottomMargin; }
@@ -48,7 +48,6 @@ public:
     void applyRootMargin(LayoutRect&) const;
     unsigned firstThresholdGreaterThan(float ratio) const;
     void deliver();
-    void disconnect();
     void removeObservation(IntersectionObservation&);
     bool hasEntries() const { return m_entries.size(); }
     const HeapHashSet<WeakMember<IntersectionObservation>>& observations() const { return m_observations; }