1. A small fix of Windows VM size.

third_party/tcmalloc/chromium/src/common.h

 // Copyright (c) 2008, 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 230 matching lines @@
 };
 
 // Allocates "bytes" worth of memory and returns it.  Increments
 // metadata_system_bytes appropriately.  May return NULL if allocation
 // fails.  Requires pageheap_lock is held.
 void* MetaDataAlloc(size_t bytes);
 
 // Returns the total number of bytes allocated from the system.
 // Requires pageheap_lock is held.
 uint64_t metadata_system_bytes();
+uint64_t metadata_unmapped_bytes();
 
 // Adjust metadata_system_bytes to indicate that bytes are actually committed.
 // Requires pageheap_lock is held.
-void increment_metadata_system_bytes(size_t bytes);
+void update_metadata_system_bytes(int diff);
+void update_metadata_unmapped_bytes(int diff);
 
 // size/depth are made the same size as a pointer so that some generic
 // code below can conveniently cast them back and forth to void*.
 static const int kMaxStackDepth = 31;
 struct StackTrace {
   uintptr_t size;          // Size of object
   uintptr_t depth;         // Number of PC values stored in array below
   void*     stack[kMaxStackDepth];
 };
 
 }  // namespace tcmalloc
 
 #endif  // TCMALLOC_COMMON_H_