Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/core/css/StyleSheetList.cpp

Index: third_party/WebKit/Source/core/css/StyleSheetList.cpp
diff --git a/third_party/WebKit/Source/core/css/StyleSheetList.cpp b/third_party/WebKit/Source/core/css/StyleSheetList.cpp
index 07210e87c70bc49cd837ee0e12c2161f5ce40e2b..b564d320f553956febb2420088968dee3ba9ed9b 100644
--- a/third_party/WebKit/Source/core/css/StyleSheetList.cpp
+++ b/third_party/WebKit/Source/core/css/StyleSheetList.cpp
@@ -36,9 +36,7 @@ StyleSheetList::StyleSheetList(TreeScope* treeScope)
 {
 }
 
-DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(StyleSheetList);
-
-inline const WillBeHeapVector<RefPtrWillBeMember<StyleSheet>>& StyleSheetList::styleSheets()
+inline const HeapVector<Member<StyleSheet>>& StyleSheetList::styleSheets()
 {
 #if !ENABLE(OILPAN)
     if (!m_treeScope)
@@ -62,7 +60,7 @@ unsigned StyleSheetList::length()
 
 StyleSheet* StyleSheetList::item(unsigned index)
 {
-    const WillBeHeapVector<RefPtrWillBeMember<StyleSheet>>& sheets = styleSheets();
+    const HeapVector<Member<StyleSheet>>& sheets = styleSheets();
     return index < sheets.size() ? sheets[index].get() : nullptr;
 }