Route calls to tcmalloc MallocExtension through allocator agnostic interface

base/allocator/allocator_extension.h

Index: base/allocator/allocator_extension.h
diff --git a/base/allocator/allocator_extension.h b/base/allocator/allocator_extension.h
new file mode 100644
index 0000000000000000000000000000000000000000..d63f189373a6182ea7401defa797618208c701d7
--- /dev/null
+++ b/base/allocator/allocator_extension.h
@@ -0,0 +1,45 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H
+#define BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H
+#pragma once
+
+#include "base/allocator/allocator_extension_thunks.h"
+#include "base/base_export.h"
+#include "build/build_config.h"
+
+namespace base {
+namespace allocator {
+
+// Request that the allocator print a human-readable description of the current
+// state of the allocator into a null-terminated string in the memory segment
+// buffer[0,buffer_length-1].
+//
+// |buffer| must point to a valid piece of memory
+// |buffer_length| must be > 0.
+BASE_EXPORT void GetStats(char* buffer, int buffer_length);
+
+// Request that the allocator release any free memory it knows about to the
+// system.
+BASE_EXPORT void ReleaseFreeMemory();
+
+
+// These settings allow specifying a callback used to implement the allocator
+// extension functions.  These are optional, but if set they must only be set
+// once.  These will typically called in an allocator-specific initialization
+// routine.
+//
+// No threading promises are made.  The caller is responsible for making sure
+// these pointers are set before any other threads attempt to call the above
+// functions.
+BASE_EXPORT void SetGetStatsFunction(
+    thunks::GetStatsFunction* get_stats_function);
+
+BASE_EXPORT void SetReleaseFreeMemoryFunction(
+    thunks::ReleaseFreeMemoryFunction* release_free_memory_function);
+}  // namespace allocator
+}  // namespace base
+
+#endif