IntersectionObserver: second cut.

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

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 10 matching lines @@
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/* STATIC_ASSERT_STRUCT_SIZES_EQUAL
+
+   Compile-time assert that a struct has the expected size.  The old way to do this is:
+
+   static_assert(sizeof(StructWithSameSize) == sizeof(Struct)), "Wrong size!");
+
+   However, static_assert will not emit the actual sizes of the structs in question, and
+   there is no way to use an interpolated string in the error message.  By contrast,
+   STATIC_ASSERT_STRUCT_SIZES_EQUAL will ensure that the actual sizes of the compared structs
+   will appear in the compiler error output.
+*/
+
 #include "config.h"
 #include "core/dom/ElementRareData.h"
-
+#include "core/dom/IntersectionObservation.h"
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 struct SameSizeAsElementRareData : NodeRareData {
     short indices[2];
     LayoutSize sizeForResizing;
     IntSize scrollOffset;
     void* pointer;
-    RawPtrWillBeMember<void*> willbeMember[11];
-    PersistentWillBeMember<void*> persistent[1];
+    RawPtrWillBeMember<void*> willbeMember[12];
+    PersistentWillBeMember<void*> persistent[3];
 };
 
 CSSStyleDeclaration& ElementRareData::ensureInlineCSSStyleDeclaration(Element* ownerElement)
 {
     if (!m_cssomWrapper)
         m_cssomWrapper = adoptPtrWillBeNoop(new InlineCSSStyleDeclaration(ownerElement));
     return *m_cssomWrapper;
 }
 
 AttrNodeList& ElementRareData::ensureAttrNodeList()
 {
     if (!m_attrNodeList)
         m_attrNodeList = adoptPtrWillBeNoop(new AttrNodeList);
     return *m_attrNodeList;
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(ElementRareData)
 {
     visitor->trace(m_dataset);
     visitor->trace(m_classList);
     visitor->trace(m_shadow);
     visitor->trace(m_attributeMap);
 #if ENABLE(OILPAN)
     visitor->trace(m_attrNodeList);
 #endif
     visitor->trace(m_elementAnimations);
     visitor->trace(m_cssomWrapper);
+    visitor->trace(m_weakPointerFactory);
     visitor->trace(m_customElementDefinition);
     visitor->trace(m_generatedBefore);
     visitor->trace(m_generatedAfter);
     visitor->trace(m_generatedFirstLetter);
     visitor->trace(m_backdrop);
+    visitor->trace(m_intersectionObservers);
+    visitor->trace(m_intersectionObservations);
     NodeRareData::traceAfterDispatch(visitor);
 }
 
 static_assert(sizeof(ElementRareData) == sizeof(SameSizeAsElementRareData), "ElementRareData should stay small");
 
 } // namespace blink