Route calls to tcmalloc MallocExtension through allocator agnostic interface

chrome/browser/memory_purger.cc

Index: chrome/browser/memory_purger.cc
diff --git a/chrome/browser/memory_purger.cc b/chrome/browser/memory_purger.cc
index 7c2fd9e0154d4cfb13048e04382ed810244f7409..ecff13ef92a47b9ddc82b9ec8de9377d69fc49dd 100644
--- a/chrome/browser/memory_purger.cc
+++ b/chrome/browser/memory_purger.cc
@@ -6,6 +6,7 @@
 
 #include <set>
 
+#include "base/allocator/allocator_extension.h"
 #include "base/bind.h"
 #include "base/threading/thread.h"
 #include "chrome/browser/browser_process.h"
@@ -22,7 +23,6 @@
 #include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
-#include "third_party/tcmalloc/chromium/src/gperftools/malloc_extension.h"
 
 using content::BrowserContext;
 using content::BrowserThread;
@@ -127,14 +127,12 @@ void MemoryPurger::PurgeBrowser() {
   // * Purge AppCache memory.  Not yet implemented sufficiently.
   // * Browser-side DatabaseTracker.  Not implemented sufficiently.
 
-#if !defined(OS_MACOSX) && defined(USE_TCMALLOC)
-  // Tell tcmalloc to release any free pages it's still holding.
+  // Tell our allocator to release any free pages it's still holding.
   //
   // TODO(pkasting): A lot of the above calls kick off actions on other threads.
   // Maybe we should find a way to avoid calling this until those actions
   // complete?
-  MallocExtension::instance()->ReleaseFreeMemory();
-#endif
+  base::allocator::ReleaseFreeMemory();
 }
 
 // static