diff --git a/public/icvar.h b/public/icvar.h
index a68f3580..9f52aea1 100644
--- a/public/icvar.h
+++ b/public/icvar.h
@@ -120,6 +120,15 @@ public:
 	virtual void QueueMaterialThreadSetValue( ConVar *, float ) = 0;
 	virtual bool HasQueuedMaterialThreadConVarSets() const = 0;
 	virtual int ProcessQueuedMaterialThreadConVarSets() = 0;
+	
+	// Returns a cvar iterator pointer.
+	//
+	// If memoverride is not used, use g_pMemAlloc->Free() to deallocate the memory
+	// used by these iterators.
+	//
+	// If memoverride is used, you can use the delete operator even though there
+	// is no virtual destructor. This can be done because memoverride overloads the
+	// delete operator so that it will call g_pMemAlloc-Free().
 	virtual ICvarIteratorInternal *FactoryInternalIterator() = 0;
 };
 
diff --git a/public/tier0/memalloc.h b/public/tier0/memalloc.h
index b1ccbf1d..35c6365b 100644
--- a/public/tier0/memalloc.h
+++ b/public/tier0/memalloc.h
@@ -74,6 +74,8 @@ public:
 	// FIXME: Make a better stats interface
 	virtual void DumpStats() = 0;
 	virtual void DumpStatsFileBase( char const *pchFileBase ) = 0;
+	
+	virtual size_t ComputeMemoryUsedBy( const char *pFileName ) = 0;
 
 	// FIXME: Remove when we have our own allocator
 	virtual void* CrtSetReportFile( int nRptType, void* hFile ) = 0;
@@ -104,6 +106,9 @@ public:
 
 	// Returns 0 if no failure, otherwise the size_t of the last requested chunk
 	virtual size_t MemoryAllocFailed() = 0;
+	
+	virtual void CompactIncremental() = 0;
+	virtual void OutOfMemory( size_t ) = 0;
 };
 
 //-----------------------------------------------------------------------------