Fix memory leak in ThreadWatcher.

chrome/browser/metrics/thread_watcher_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.
 
 #include "chrome/browser/metrics/thread_watcher.h"
 
 #include <math.h>
 #include <stdint.h>
 
 #include <memory>
@@ skipping 261 matching lines @@
     WaitForSetUp(TimeDelta::FromMinutes(1));
   }
 
   void SetUpObjects() {
     DCHECK(WatchDogThread::CurrentlyOnWatchDogThread());
 
     // Setup the registry for thread watchers.
     thread_watcher_list_ = new ThreadWatcherList();
 
     // Create thread watcher object for the IO thread.
-    io_watcher_ = new CustomThreadWatcher(BrowserThread::IO, kIOThreadName,
-                                          kSleepTime, kUnresponsiveTime);
+    std::unique_ptr<CustomThreadWatcher> io_watcher(
+        new CustomThreadWatcher(BrowserThread::IO, kIOThreadName,
+                                kSleepTime, kUnresponsiveTime));
+    io_watcher_ = io_watcher.get();
+    EXPECT_TRUE(ThreadWatcherList::Register(std::move(io_watcher)));

[Ilya Sherman, 2016/08/31 03:54:42]

nit: This should be an ASSERT_TRUE, as the following line would crash if the
watcher were somehow not registered.

[Joshua LeVasseur, 2016/08/31 19:06:50]

Done.

     EXPECT_EQ(io_watcher_, thread_watcher_list_->Find(BrowserThread::IO));
 
     // Create thread watcher object for the DB thread.
-    db_watcher_ = new CustomThreadWatcher(BrowserThread::DB, kDBThreadName,
-                                          kSleepTime, kUnresponsiveTime);
+    std::unique_ptr<CustomThreadWatcher> db_watcher(
+        new CustomThreadWatcher(BrowserThread::DB, kDBThreadName,
+                                kSleepTime, kUnresponsiveTime));
+    db_watcher_ = db_watcher.get();
+    EXPECT_TRUE(ThreadWatcherList::Register(std::move(db_watcher)));

[Ilya Sherman, 2016/08/31 03:54:42]

Ditto.

[Joshua LeVasseur, 2016/08/31 19:06:50]

Done.

     EXPECT_EQ(db_watcher_, thread_watcher_list_->Find(BrowserThread::DB));
 
     {
       base::AutoLock lock(lock_);
       initialized_ = true;
     }
     setup_complete_.Signal();
   }
 
   void WaitForSetUp(TimeDelta wait_time) {
@@ skipping 515 matching lines @@
 }
 
 TEST_F(JankTimeBombTest, ArmTest) {
   // Test firing of Alarm by passing empty delay.
   TestingJankTimeBomb timebomb((base::TimeDelta()));
   if (!timebomb.IsEnabled())
     return;
   WaitForWatchDogThreadPostTask();
   EXPECT_TRUE(timebomb.alarm_invoked());
 }