[ios] Use SpinRunLoopWithMinDelay in MetaTagsTestCase.

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"
 
@@ skipping 21 matching lines @@
 
 // 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.
+// within the given maximum delay. This method may return before max_delay
+// elapsed.
 void SpinRunLoopWithMaxDelay(TimeDelta max_delay);
 
+// Lets the run loop of the current thread process other messages
+// within the given minimum delay. This method returns after |min_delay|
+// elapsed.
+void SpinRunLoopWithMinDelay(TimeDelta min_delay);
+
 }  // namespace ios
 }  // namespace test
 }  // namespace base
 
 #endif  // BASE_TEST_IOS_WAIT_UTIL_H_