Update the tcmalloc chromium branch to r144 (gperftools 2.0), and merge chromium-specific changes.

third_party/tcmalloc/chromium/src/windows/port.cc

Index: third_party/tcmalloc/chromium/src/windows/port.cc
diff --git a/third_party/tcmalloc/chromium/src/windows/port.cc b/third_party/tcmalloc/chromium/src/windows/port.cc
index ec01fd60c9583a74249fe5faf459aca03995758e..e3e2a95c9e03d8e730afc3d54549c21b9c6ac5f8 100644
--- a/third_party/tcmalloc/chromium/src/windows/port.cc
+++ b/third_party/tcmalloc/chromium/src/windows/port.cc
@@ -219,10 +219,6 @@ extern "C" int perftools_pthread_once(pthread_once_t *once_control,
 // -----------------------------------------------------------------------
 // These functions replace system-alloc.cc
 
-// The current system allocator. Because we don't link with system-alloc.cc,
-// we need to define our own.
-SysAllocator* sys_alloc = NULL;
-
 // This is mostly like MmapSysAllocator::Alloc, except it does these weird
 // munmap's in the middle of the page, which is forbidden in windows.
 extern void* TCMalloc_SystemAlloc(size_t size, size_t *actual_size,
@@ -338,6 +334,9 @@ void DumpSystemAllocatorStats(TCMalloc_Printer* printer) {
   // We don't dump stats on windows, right now
 }
 
+// The current system allocator
+SysAllocator* sys_alloc = NULL;
+
 
 // -----------------------------------------------------------------------
 // These functions rework existing functions of the same name in the