Make classes and structures in core/style, core/plugins and core/streams fast-allocated.

Source/core/plugins/testing/DictionaryPluginPlaceholder.h

Index: Source/core/plugins/testing/DictionaryPluginPlaceholder.h
diff --git a/Source/core/plugins/testing/DictionaryPluginPlaceholder.h b/Source/core/plugins/testing/DictionaryPluginPlaceholder.h
index 60ba5046ecb46d19f8f087ca7ff13a6df3a84050..1d22f1d25bfeedbae2fbb9a8a5533f428d9a33f4 100644
--- a/Source/core/plugins/testing/DictionaryPluginPlaceholder.h
+++ b/Source/core/plugins/testing/DictionaryPluginPlaceholder.h
@@ -14,8 +14,9 @@ namespace blink {
 
 // Manipulates a plugin placeholder element based on a fixed dictionary given.
 // Used for layout tests that examine the formatting of structured placeholders.
-class DictionaryPluginPlaceholder : public NoBaseWillBeGarbageCollected<DictionaryPluginPlaceholder>, public PluginPlaceholder {
+class DictionaryPluginPlaceholder final : public NoBaseWillBeGarbageCollected<DictionaryPluginPlaceholder>, public PluginPlaceholder {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(DictionaryPluginPlaceholder);
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(DictionaryPluginPlaceholder);
 public:
     static PassOwnPtrWillBeRawPtr<DictionaryPluginPlaceholder> create(Document& document, const PluginPlaceholderOptions& options)
     {