[WeakMemoryCache] Field-Trial: Make Reference from MemoryCache to Resource weak

third_party/WebKit/Source/core/fetch/Resource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 16 matching lines @@
 #include "core/fetch/CrossOriginAccessControl.h"
 #include "core/fetch/FetchInitiatorTypeNames.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/fetch/ResourceClient.h"
 #include "core/fetch/ResourceClientOrObserverWalker.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/fetch/ResourceLoader.h"
 #include "core/inspector/InstanceCounters.h"
 #include "platform/Histogram.h"
 #include "platform/Logging.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/SharedBuffer.h"
 #include "platform/TraceEvent.h"
 #include "platform/network/HTTPParsers.h"
 #include "platform/weborigin/KURL.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebScheduler.h"
 #include "public/platform/WebSecurityOrigin.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/MathExtras.h"
 #include "wtf/StdLibExtras.h"
@@ skipping 521 matching lines @@
 {
     if (!m_data)
         return false;
 
     if (!m_data->isLocked())
         return true;
 
     if (!memoryCache()->contains(this) || hasClientsOrObservers() || !m_revalidatingRequest.isNull() || !m_loadFinishTime || !isSafeToUnlock())
         return false;
 
+    if (RuntimeEnabledFeatures::doNotUnlockSharedBufferEnabled())
+        return false;
+
     m_data->unlock();
     return true;
 }
 
 void Resource::responseReceived(const ResourceResponse& response, PassOwnPtr<WebDataConsumerHandle>)
 {
     m_responseTimestamp = currentTime();
 
     if (!m_revalidatingRequest.isNull()) {
         if (response.httpStatusCode() == 304) {
@@ skipping 541 matching lines @@
     case Resource::Media:
         return "Media";
     case Resource::Manifest:
         return "Manifest";
     }
     ASSERT_NOT_REACHED();
     return "Unknown";
 }
 
 } // namespace blink