Suppress unitialized use of memory for random_number_ seed

base/tracked_objects.cc

Index: base/tracked_objects.cc
===================================================================
--- base/tracked_objects.cc	(revision 112930)
+++ base/tracked_objects.cc	(working copy)
@@ -9,6 +9,7 @@
 #include "base/format_macros.h"
 #include "base/message_loop.h"
 #include "base/stringprintf.h"
+#include "base/third_party/valgrind/memcheck.h"
 #include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 #include "base/port.h"
@@ -218,6 +219,8 @@
 ThreadData::~ThreadData() {}
 
 void ThreadData::PushToHeadOfList() {
+  VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE(&random_number_,
+                                           sizeof(random_number_));
   // Toss in a hint of randomness (atop the uniniitalized value).
   random_number_ += static_cast<int32>(this - static_cast<ThreadData*>(0));
   random_number_ ^= (Now() - TrackedTime()).InMilliseconds();