Allow eviction of ImageBitmaps that are created from ImageElements.

Source/core/loader/cache/CachedResource.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 88 matching lines @@
     , m_cancelTimer(this, &CachedResource::cancelTimerFired)
     , m_lastDecodedAccessTime(0)
     , m_loadFinishTime(0)
     , m_identifier(0)
     , m_encodedSize(0)
     , m_decodedSize(0)
     , m_accessCount(0)
     , m_handleCount(0)
     , m_preloadCount(0)
     , m_preloadResult(PreloadNotReferenced)
+    , m_cachePriority(CachePriorityLow)
     , m_inLiveDecodedResourcesList(false)
     , m_requestedFromNetworkingLayer(false)
     , m_inCache(false)
     , m_loading(false)
     , m_switchingClientsToRevalidatedResource(false)
     , m_type(type)
     , m_status(Pending)
 #ifndef NDEBUG
     , m_deleted(false)
     , m_lruIndex(0)
@@ skipping 217 matching lines @@
     WebKit::Platform::current()->cacheMetadata(m_response.url(), m_response.responseTime(), serializedData.data(), serializedData.size());
 }
 
 CachedMetadata* CachedResource::cachedMetadata(unsigned dataTypeID) const
 {
     if (!m_cachedMetadata || m_cachedMetadata->dataTypeID() != dataTypeID)
         return 0;
     return m_cachedMetadata.get();
 }
 
+void CachedResource::setCachePriority(CachePriority priority)
+{
+    m_lastDecodedAccessTime = currentTime();
+    if (inCache()) {
+        if (m_inLiveDecodedResourcesList && m_cachePriority != priority) {
+            memoryCache()->removeFromLiveDecodedResourcesList(this);
+            m_cachePriority = priority;
+            memoryCache()->insertInLiveDecodedResourcesList(this);
+        }
+        memoryCache()->prune();
+    }
+}
+
 void CachedResource::clearLoader()
 {
     m_loader = 0;
 }
 
 void CachedResource::addClient(CachedResourceClient* client)
 {
     if (addClientToSet(client))
         didAddClient(client);
 }
@@ skipping 462 matching lines @@
     if (m_callbackTimer.isActive())
         m_callbackTimer.stop();
 }
 
 void CachedResource::CachedResourceCallback::timerFired(Timer<CachedResourceCallback>*)
 {
     m_resource->didAddClient(m_client);
 }
 
 }
+