Move FontResourceClient to Oilpan heap

third_party/WebKit/Source/core/fetch/ResourceOwner.h

 /*
  * Copyright (C) 2013 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 14 matching lines @@
  * 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.
  */
 
 #ifndef ResourceOwner_h
 #define ResourceOwner_h
 
 #include "core/fetch/Resource.h"
+#include <type_traits>
 
 namespace blink {
 
+template <typename R, typename C, bool isClientGarbageCollectedMixin>

[hiroshige, 2016/05/27 08:18:38]

|R| is not necessary?

nit optional: How about renaming |C| to |Client|, to make it consistent with
|isClientGarbageCollectedMixin|?

[yhirano, 2016/05/27 16:37:28]

Done.

+class ResourceOwnerBase;
+
+template <typename R, typename C>
+class ResourceOwnerBase<R, C, true> : public C {
+public:
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        C::trace(visitor);
+    }
+};
+
+// TODO(yhirano): Remove this template once all ResourceClients become
+// GarbageCollectedMixin.
+template <typename R, typename C>
+class ResourceOwnerBase<R, C, false> : public GarbageCollectedMixin, public C {
+public:
+    DEFINE_INLINE_VIRTUAL_TRACE() {}
+};
+
 template<class R, class C = typename R::ClientType>
-class ResourceOwner : public GarbageCollectedMixin, public C {
+class ResourceOwner : public ResourceOwnerBase<R, C, std::is_base_of<GarbageCollectedMixin, C>::value> {
     USING_PRE_FINALIZER(ResourceOwner, clearResource);
 public:
     using ResourceType = R;
+    ~ResourceOwner() override {}
+    ResourceType* resource() const { return m_resource; }
 
-    virtual ~ResourceOwner();
-    ResourceType* resource() const { return m_resource.get(); }
-
-    DEFINE_INLINE_VIRTUAL_TRACE() { visitor->trace(m_resource); }
+    DEFINE_INLINE_TRACE()
+    {
+        visitor->trace(m_resource);
+        ResourceOwnerBase<R, C, std::is_base_of<GarbageCollectedMixin, C>::value>::trace(visitor);
+    }
 
 protected:
-    ResourceOwner();
+    ResourceOwner()
+    {
+        ThreadState::current()->registerPreFinalizer(this);
+    }
 
     void setResource(ResourceType*);
     void clearResource() { setResource(nullptr); }
 
 private:
     Member<ResourceType> m_resource;
 };
 
 template<class R, class C>
-inline ResourceOwner<R, C>::ResourceOwner()
-{
-    ThreadState::current()->registerPreFinalizer(this);
-}
-
-template<class R, class C>
-inline ResourceOwner<R, C>::~ResourceOwner()
-{
-}
-
-template<class R, class C>
 inline void ResourceOwner<R, C>::setResource(R* newResource)
 {
     if (newResource == m_resource)
         return;
 
     // Some ResourceClient implementations reenter this so
     // we need to prevent double removal.
     if (ResourceType* oldResource = m_resource.release())
         oldResource->removeClient(this);
 
     if (newResource) {
         m_resource = newResource;
         m_resource->addClient(this);
     }
 }
 
 } // namespace blink
 
 #endif