Route calls to tcmalloc MallocExtension through allocator agnostic interface

base/allocator/allocator_extension.cc

Index: base/allocator/allocator_extension.cc
diff --git a/base/allocator/allocator_extension.cc b/base/allocator/allocator_extension.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7ae11da3e301121f328b265dac2bf489d3c5b52e
--- /dev/null
+++ b/base/allocator/allocator_extension.cc
@@ -0,0 +1,42 @@
+// 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.
+
+#include "base/allocator/allocator_extension.h"
+
+#include "base/logging.h"
+
+namespace base {
+namespace allocator {
+
+void GetStats(char* buffer, int buffer_length) {
+  DCHECK_GT(buffer_length, 0);
+  if (thunks::GetStatsFunction* get_stats_function =
+          base::allocator::thunks::GetGetStatsFunction())
+    get_stats_function(buffer, buffer_length);
+  else
+    buffer[0] = '\0';
+}
+
+void ReleaseFreeMemory() {
+  if (thunks::ReleaseFreeMemoryFunction* release_free_memory_function =
+          base::allocator::thunks::GetReleaseFreeMemoryFunction())
+    release_free_memory_function();
+}
+
+void SetGetStatsFunction(thunks::GetStatsFunction* get_stats_function) {
+  DCHECK_EQ(base::allocator::thunks::GetGetStatsFunction(),
+            reinterpret_cast<thunks::GetStatsFunction*>(NULL));
+  base::allocator::thunks::SetGetStatsFunction(get_stats_function);
+}
+
+void SetReleaseFreeMemoryFunction(
+    thunks::ReleaseFreeMemoryFunction* release_free_memory_function) {
+  DCHECK_EQ(base::allocator::thunks::GetReleaseFreeMemoryFunction(),
+            reinterpret_cast<thunks::ReleaseFreeMemoryFunction*>(NULL));
+  base::allocator::thunks::SetReleaseFreeMemoryFunction(
+      release_free_memory_function);
+}
+
+}  // namespace allocator
+}  // namespace base