[NOT TO COMMIT!] Merge Chromium-specific changes in tcmalloc thru. the original gperftools r136.

third_party/tcmalloc/chromium/src/malloc_hook.cc

Index: third_party/tcmalloc/chromium/src/malloc_hook.cc
diff --git a/third_party/tcmalloc/chromium/src/malloc_hook.cc b/third_party/tcmalloc/chromium/src/malloc_hook.cc
index 12fd32725d0f94daacbd57bfd0fbb7bcaa43a686..f787d91a68e16eafff69972f4cd60052ec8d1c80 100644
--- a/third_party/tcmalloc/chromium/src/malloc_hook.cc
+++ b/third_party/tcmalloc/chromium/src/malloc_hook.cc
@@ -127,7 +127,7 @@ void InitialPreMMapHook(const void* start,
   MallocHook::InvokePreMmapHook(start, size, protection, flags, fd, offset);
 }
 
-void InitialPreSbrkHook(ptrdiff_t increment) {
+void InitialPreSbrkHook(std::ptrdiff_t increment) {
   perftools_pthread_once(&once, &RemoveInitialHooksAndCallInitializers);
   MallocHook::InvokePreSbrkHook(increment);
 }
@@ -581,11 +581,11 @@ void MallocHook::InvokeMremapHookSlow(const void* result,
                                            flags, new_addr));
 }
 
-void MallocHook::InvokePreSbrkHookSlow(ptrdiff_t increment) {
+void MallocHook::InvokePreSbrkHookSlow(std::ptrdiff_t increment) {
   INVOKE_HOOKS(PreSbrkHook, presbrk_hooks_, (increment));
 }
 
-void MallocHook::InvokeSbrkHookSlow(const void* result, ptrdiff_t increment) {
+void MallocHook::InvokeSbrkHookSlow(const void* result, std::ptrdiff_t increment) {
   INVOKE_HOOKS(SbrkHook, sbrk_hooks_, (result, increment));
 }