Improve DEFINE_STATIC_LOCAL()'s handling of Blink GCed objects.

third_party/WebKit/Source/platform/fonts/FontCache.cpp

 /*
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 279 matching lines @@
 
     purgePlatformFontDataCache();
     purgeFontVerticalDataCache();
     purgeFallbackListShaperCache();
 }
 
 static bool invalidateFontCache = false;
 
 HeapHashSet<WeakMember<FontCacheClient>>& fontCacheClients()
 {
-    DEFINE_STATIC_LOCAL(Persistent<HeapHashSet<WeakMember<FontCacheClient>>>, clients, (new HeapHashSet<WeakMember<FontCacheClient>>()));
+    DEFINE_STATIC_LOCAL(HeapHashSet<WeakMember<FontCacheClient>>, clients, (new HeapHashSet<WeakMember<FontCacheClient>>));
     invalidateFontCache = true;
-    return *clients;
+    return clients;
 }
 
 void FontCache::addClient(FontCacheClient* client)
 {
     ASSERT(!fontCacheClients().contains(client));
     fontCacheClients().add(client);
 }
 
 #if !ENABLE(OILPAN)
 void FontCache::removeClient(FontCacheClient* client)
@@ skipping 64 matching lines @@
         iter != gFallbackListShaperCache->end();
         ++iter) {
         shapeResultCacheSize += iter->value->byteSize();
     }
     dump->addScalar("size", "bytes", shapeResultCacheSize);
     memoryDump->addSuballocation(dump->guid(), String(WTF::Partitions::kAllocatedObjectPoolName));
 }
 
 
 } // namespace blink