Fix memory leak in ThreadWatcher.

chrome/browser/metrics/thread_watcher_unittest.cc

Index: chrome/browser/metrics/thread_watcher_unittest.cc
diff --git a/chrome/browser/metrics/thread_watcher_unittest.cc b/chrome/browser/metrics/thread_watcher_unittest.cc
index 4aca262b664fda495d657724d99aeec98ba7856d..ef7192e1f5e25dd035e8792a174d85baf42371ce 100644
--- a/chrome/browser/metrics/thread_watcher_unittest.cc
+++ b/chrome/browser/metrics/thread_watcher_unittest.cc
@@ -279,13 +279,19 @@ class ThreadWatcherTest : public ::testing::Test {
     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));
 
     {