Expose ReleaseFreeMemory to free up memory on memory pressure or idle cleanup.

Source/wtf/PartitionAlloc.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 352 matching lines @@
 // partitionDumpStatsGeneric for using the memory statistics.
 class WTF_EXPORT PartitionStatsDumper {
 public:
     virtual void partitionsDumpBucketStats(const char* partitionName, const PartitionBucketMemoryStats*) = 0;
 };
 
 WTF_EXPORT void partitionAllocInit(PartitionRoot*, size_t numBuckets, size_t maxAllocation);
 WTF_EXPORT bool partitionAllocShutdown(PartitionRoot*);
 WTF_EXPORT void partitionAllocGenericInit(PartitionRootGeneric*);
 WTF_EXPORT bool partitionAllocGenericShutdown(PartitionRootGeneric*);
-WTF_EXPORT void partitionPurgeMemory(PartitionRootBase*);
+WTF_EXPORT void partitionPurgeMemory(PartitionRoot*);
+WTF_EXPORT void partitionPurgeMemoryGeneric(PartitionRootGeneric*);
 
 WTF_EXPORT NEVER_INLINE void* partitionAllocSlowPath(PartitionRootBase*, int, size_t, PartitionBucket*);
 WTF_EXPORT NEVER_INLINE void partitionFreeSlowPath(PartitionPage*);
 WTF_EXPORT NEVER_INLINE void* partitionReallocGeneric(PartitionRootGeneric*, void*, size_t);
 
 WTF_EXPORT void partitionDumpStats(PartitionRoot*, const char* partitionName, PartitionStatsDumper*);
 WTF_EXPORT void partitionDumpStatsGeneric(PartitionRootGeneric*, const char* partitionName, PartitionStatsDumper*);
 
 ALWAYS_INLINE PartitionFreelistEntry* partitionFreelistMask(PartitionFreelistEntry* ptr)
 {
@@ skipping 347 matching lines @@
 using WTF::partitionAlloc;
 using WTF::partitionFree;
 using WTF::partitionAllocGeneric;
 using WTF::partitionFreeGeneric;
 using WTF::partitionReallocGeneric;
 using WTF::partitionAllocActualSize;
 using WTF::partitionAllocSupportsGetSize;
 using WTF::partitionAllocGetSize;
 
 #endif // WTF_PartitionAlloc_h