Add a UseCounter that measures the amount of memory used in PartitionAlloc

Source/wtf/Partitions.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 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef Partitions_h
 #define Partitions_h
 
 #include "wtf/PartitionAlloc.h"
+#include "wtf/WTF.h"
 #include "wtf/WTFExport.h"
 
 namespace WTF {
 
 class WTF_EXPORT Partitions {
 public:
-    static void initialize();
+    static void initialize(HistogramEnumerationFunction = nullptr);
     static void shutdown();
     ALWAYS_INLINE static PartitionRootGeneric* getBufferPartition()
     {
         // TODO(haraken): This check is needed because some call sites allocate
         // Blink things before WTF::initialize(). We should fix those call sites
         // and remove the check.
         if (UNLIKELY(!s_initialized))
             initialize();
         return m_bufferAllocator.root();
     }
@@ skipping 28 matching lines @@
     static size_t totalSizeOfCommittedPages()
     {
         size_t totalSize = 0;
         totalSize += m_fastMallocAllocator.root()->totalSizeOfCommittedPages;
         totalSize += m_bufferAllocator.root()->totalSizeOfCommittedPages;
         totalSize += m_objectModelAllocator.root()->totalSizeOfCommittedPages;
         totalSize += m_renderingAllocator.root()->totalSizeOfCommittedPages;
         return totalSize;
     }
 
+    static void notifyCommittedMemoryChanged();
+
 private:
     static bool s_initialized;
     static PartitionAllocatorGeneric m_fastMallocAllocator;
     static PartitionAllocatorGeneric m_bufferAllocator;
     static SizeSpecificPartitionAllocator<3328> m_objectModelAllocator;
     static SizeSpecificPartitionAllocator<1024> m_renderingAllocator;
+    static HistogramEnumerationFunction m_histogramEnumeration;
 };
 
 } // namespace WTF
 
 #endif // Partitions_h