Change EXPECT/ASSERT_DCHECK_DEATH macro to not expose the |regex| parameter.

base/task_scheduler/task_tracker_unittest.cc

Index: base/task_scheduler/task_tracker_unittest.cc
diff --git a/base/task_scheduler/task_tracker_unittest.cc b/base/task_scheduler/task_tracker_unittest.cc
index 2602e3735b0ef129fb585b00ef043ae3e8d997f9..fedb215669889f409018bfa0b2577cc4051ffb3e 100644
--- a/base/task_scheduler/task_tracker_unittest.cc
+++ b/base/task_scheduler/task_tracker_unittest.cc
@@ -354,7 +354,7 @@ TEST_P(TaskSchedulerTaskTrackerTest, WillPostAfterShutdown) {
 
   // |task_tracker_| shouldn't allow a task to be posted after shutdown.
   if (GetParam() == TaskShutdownBehavior::BLOCK_SHUTDOWN) {
-    EXPECT_DCHECK_DEATH({ tracker_.WillPostTask(task.get()); }, "");
+    EXPECT_DCHECK_DEATH({ tracker_.WillPostTask(task.get()); });
   } else {
     EXPECT_FALSE(tracker_.WillPostTask(task.get()));
   }
@@ -386,8 +386,7 @@ TEST_P(TaskSchedulerTaskTrackerTest, SingletonAllowed) {
         {
           tracker.RunNextTaskInSequence(
               CreateSequenceWithTask(std::move(task)).get());
-        },
-        "");
+        });
   }
 }