Enable TCMalloc on Linux by default.

base/process_util_linux.cc

Index: base/process_util_linux.cc
diff --git a/base/process_util_linux.cc b/base/process_util_linux.cc
index 25f1c2708e65a2c9b3065cbb22f347eea4fee95a..12ffe302a1980d37e940bb317dce9f189c6633bb 100644
--- a/base/process_util_linux.cc
+++ b/base/process_util_linux.cc
@@ -514,11 +514,7 @@ void OnNoMemory() {
 
 extern "C" {
 
-#if defined(LINUX_USE_TCMALLOC)
-
-int tc_set_new_mode(int mode);
-
-#else  // defined(LINUX_USE_TCMALLOC)
+#if !defined(LINUX_USE_TCMALLOC)
 
 typedef void* (*malloc_type)(size_t size);
 typedef void* (*valloc_type)(size_t size);
@@ -584,7 +580,7 @@ DIE_ON_OOM_2(memalign, size_t)
 
 DIE_ON_OOM_3INT(posix_memalign)
 
-#endif  // defined(LINUX_USE_TCMALLOC)
+#endif  // !defined(LINUX_USE_TCMALLOC)
 
 }  // extern C
 
@@ -593,10 +589,6 @@ void EnableTerminationOnOutOfMemory() {
   std::set_new_handler(&OnNoMemory);
   // If we're using glibc's allocator, the above functions will override
   // malloc and friends and make them die on out of memory.
-#if defined(LINUX_USE_TCMALLOC)
-  // For tcmalloc, we just need to tell it to behave like new.
-  tc_set_new_mode(1);
-#endif
 }
 
 }  // namespace base