Ensure Freed TLS Slots Contain nullptr on Reallocation

base/threading/thread_local_storage_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <process.h>
 #endif
 
 #include "base/macros.h"
@@ skipping 110 matching lines @@
     delete threads[index];
     delete thread_delegates[index];
 
     // Verify that the destructor was called and that we reset.
     EXPECT_EQ(values[index], kFinalTlsValue);
   }
   tls_slot.Free();  // Stop doing callbacks to cleanup threads.
 }
 
 TEST(ThreadLocalStorageTest, TLSReclaim) {
-  // Creates and destroys many TLS slots.
+  // Creates and destroys many TLS slots and ensures they all zero-inited.
   for (int i = 0; i < 1000; ++i) {
     ThreadLocalStorage::Slot slot(nullptr);
+    EXPECT_EQ(nullptr, slot.Get());
+    slot.Set(reinterpret_cast<void*>(0xBAADF00D));
+    EXPECT_EQ(reinterpret_cast<void*>(0xBAADF00D), slot.Get());
   }
 }
 
 }  // namespace base