DO NOT COMMIT: Experimental removal of encoded image data

third_party/WebKit/Source/core/fetch/MemoryCache.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) 2004, 2005, 2006, 2007, 2008 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
     version 2 of the License, or (at your option) any later version.
@@ skipping 270 matching lines @@
         }
         current = previous;
     }
 }
 
 void MemoryCache::pruneDeadResources(PruneStrategy strategy)
 {
     size_t capacity = deadCapacity();
     if (strategy == MaximalPrune)
         capacity = 0;
-    if (!m_deadSize || (capacity && m_deadSize <= capacity))
-        return;
+
+    // Now pruneDeadResources needs to check all resources when the strategy is Maximal
+    if (strategy != MaximalPrune) {
+        if (!m_deadSize || (capacity && m_deadSize <= capacity))
+            return;
+    }
 
     size_t targetSize = static_cast<size_t>(capacity * cTargetPrunePercentage); // Cut by a percentage to avoid immediately pruning again.
 
     int size = m_allResources.size();
     if (targetSize && m_deadSize <= targetSize)
         return;
 
     bool canShrinkLRULists = true;
     for (int i = size - 1; i >= 0; i--) {
         // Remove from the tail, since this is the least frequently accessed of the objects.
         MemoryCacheEntry* current = m_allResources[i].m_tail;
 
         // First flush all the decoded data in this queue.
         while (current) {
             Resource* resource = current->resource();
             MemoryCacheEntry* previous = current->m_previousInAllResourcesList;
 
             // Decoded data may reference other resources. Skip |current| if
             // |current| somehow got kicked out of cache during
             // destroyDecodedData().
             if (!resource || !contains(resource)) {
                 current = previous;
                 continue;
             }
 
+            if (strategy == MaximalPrune) {
+                if (!resource->isPreloaded() && resource->isLoaded() && resource->isReloadable()) {
+                    resource->myPrune();
+                }
+            }
+
             if (!resource->isAlive() && !resource->isPreloaded() && resource->isLoaded()) {
                 // Destroy our decoded data. This will remove us from
                 // m_liveDecodedResources, and possibly move us to a different
                 // LRU list in m_allResources.
                 resource->prune();
 
                 if (targetSize && m_deadSize <= targetSize)
                     return;
             }
             current = previous;
@@ skipping 418 matching lines @@
 bool MemoryCache::isInSameLRUListForTest(const Resource* x, const Resource* y)
 {
     MemoryCacheEntry* ex = getEntryForResource(x);
     MemoryCacheEntry* ey = getEntryForResource(y);
     ASSERT(ex);
     ASSERT(ey);
     return lruListFor(ex->m_accessCount, x->size()) == lruListFor(ey->m_accessCount, y->size());
 }
 
 } // namespace blink