Reintroducing MallocHooks changes with fix for infinite loop in MallocHooks on Platform::Exit.

runtime/BUILD.gn

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
+import("runtime_args.gni")
+
 declare_args() {
   # Instead of using is_debug, we introduce a different flag for specifying a
   # Debug build of Dart so that clients can still use a Release build of Dart
   # while themselves doing a Debug build.
   dart_debug = false
 
   # Set the runtime mode. This affects how the runtime is built and what
   # features it has. Valid values are:
   # 'develop' (the default) - VM is built to run as a JIT with all development
   # features enabled.
@@ skipping 124 matching lines @@
       assert(false)
     }
   }
 
   if (dart_debug) {
     defines += [ "DEBUG" ]
   } else {
     defines += [ "NDEBUG" ]
   }
 
+  include_dirs = []
+  if (dart_use_tcmalloc) {
+    defines += [ "DART_USE_TCMALLOC" ]
+    include_dirs += [ "../third_party/tcmalloc/gperftools/src" ]
+  }
+
   if (!is_win) {
     cflags = [
       "-Werror",
       "-Wall",
       "-Wextra",  # Also known as -W.
       "-Wno-unused-parameter",
       "-Wnon-virtual-dtor",
       "-Wvla",
       "-Wno-conversion-null",
       "-Woverloaded-virtual",
@@ skipping 131 matching lines @@
     "third_party/double-conversion/src:libdouble_conversion",
     "vm:libdart_lib",
     "vm:libdart_lib_nosnapshot",
     "vm:libdart_vm",
     "vm:libdart_vm_nosnapshot",
   ]
   sources = [
     "vm/libdart_dependency_helper.cc",
   ]
 }