Update from https://crrev.com/327068

base/test/ios/wait_util.h

+// Copyright 2014 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.
+
+#ifndef BASE_TEST_IOS_WAIT_UTIL_H_
+#define BASE_TEST_IOS_WAIT_UTIL_H_
+
+#include "base/ios/block_types.h"
+#include "base/time/time.h"
+
+namespace base {
+
+class MessageLoop;
+
+namespace test {
+namespace ios {
+
+// Returns the time spent in running |action| plus waiting until |condition| is
+// met.
+// Performs |action| and then spins run loop and runs the |message_loop| until
+// |condition| block returns true.
+// |action| may be nil if no action needs to be performed before the wait loop.
+// |message_loop| can be null if there is no need to spin the message loop.
+// |condition| may be nil if there is no condition to wait for: the run loop
+// will spin until timeout is reached.
+// |timeout| parameter sets the maximum wait time. If |timeout| is zero,
+// a reasonable default will be used.
+TimeDelta TimeUntilCondition(ProceduralBlock action,
+                             ConditionBlock condition,
+                             MessageLoop* message_loop,
+                             TimeDelta timeout);
+
+// Waits until |condition| is met. A |message_loop| to spin and a |timeout| can
+// be optionally passed; if |timeout| is zero, a reasonable default will be
+// used.
+void WaitUntilCondition(ConditionBlock condition,
+                        MessageLoop* message_loop,
+                        TimeDelta timeout);
+void WaitUntilCondition(ConditionBlock condition);
+
+// Lets the run loop of the current thread process other messages
+// within the given maximum delay.
+void SpinRunLoopWithMaxDelay(TimeDelta max_delay);
+
+}  // namespace ios
+}  // namespace test
+}  // namespace base
+
+#endif  // BASE_TEST_IOS_WAIT_UTIL_H_