[tracing] fix a data race in MemoryDumpManager

base/trace_event/memory_dump_manager_unittest.cc

 // Copyright 2015 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.
 
 #include "base/trace_event/memory_dump_manager.h"
 
 #include "base/bind_helpers.h"
 #include "base/memory/scoped_vector.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
@@ skipping 173 matching lines @@
 
   // Enable both mdp1 and mdp2.
   mdm_->RegisterDumpProvider(&mdp1);
   EnableTracing(kTraceCategory);
   EXPECT_CALL(mdp1, OnMemoryDump(_)).Times(1).WillRepeatedly(Return(true));
   EXPECT_CALL(mdp2, OnMemoryDump(_)).Times(1).WillRepeatedly(Return(true));
   mdm_->RequestGlobalDump(MemoryDumpType::EXPLICITLY_TRIGGERED);
   DisableTracing();
 }
 
-// Fails on Linux TSan. http://crbug.com/499983
-#if defined(OS_LINUX)
-#define MAYBE_RespectTaskRunnerAffinity DISABLED_RespectTaskRunnerAffinity
-#else
-#define MAYBE_RespectTaskRunnerAffinity RespectTaskRunnerAffinity
-#endif
-
 // Checks that the MemoryDumpManager respects the thread affinity when a
 // MemoryDumpProvider specifies a task_runner(). The test starts creating 8
 // threads and registering a MemoryDumpProvider on each of them. At each
 // iteration, one thread is removed, to check the live unregistration logic.
-TEST_F(MemoryDumpManagerTest, MAYBE_RespectTaskRunnerAffinity) {
+TEST_F(MemoryDumpManagerTest, RespectTaskRunnerAffinity) {
   const uint32 kNumInitialThreads = 8;
 
   ScopedVector<Thread> threads;
   ScopedVector<MockDumpProvider> mdps;
 
   // Create the threads and setup the expectations. Given that at each iteration
   // we will pop out one thread/MemoryDumpProvider, each MDP is supposed to be
   // invoked a number of times equal to its index.
   for (uint32 i = kNumInitialThreads; i > 0; --i) {
     threads.push_back(new Thread("test thread"));
@@ skipping 58 matching lines @@
 
   EXPECT_CALL(mdp1, OnMemoryDump(_)).Times(0);
   EXPECT_CALL(mdp2, OnMemoryDump(_)).Times(1).WillRepeatedly(Return(false));
   mdm_->RequestGlobalDump(MemoryDumpType::EXPLICITLY_TRIGGERED);
 
   DisableTracing();
 }
 
 }  // namespace trace_event
 }  // namespace base