Enable strict-virtual-specifiers for iOS builds.

base/message_loop/message_pump_io_ios.h

 // Copyright 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.
 
 #ifndef BASE_MESSAGE_LOOP_MESSAGE_PUMP_IO_IOS_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_PUMP_IO_IOS_H_
 
 #include "base/base_export.h"
 #include "base/mac/scoped_cffiledescriptorref.h"
 #include "base/mac/scoped_cftyperef.h"
@@ skipping 79 matching lines @@
     DISALLOW_COPY_AND_ASSIGN(FileDescriptorWatcher);
   };
 
   enum Mode {
     WATCH_READ = 1 << 0,
     WATCH_WRITE = 1 << 1,
     WATCH_READ_WRITE = WATCH_READ | WATCH_WRITE
   };
 
   MessagePumpIOSForIO();
-  virtual ~MessagePumpIOSForIO();
+  ~MessagePumpIOSForIO() override;
 
   // Have the current thread's message loop watch for a a situation in which
   // reading/writing to the FD can be performed without blocking.
   // Callers must provide a preallocated FileDescriptorWatcher object which
   // can later be used to manage the lifetime of this event.
   // If a FileDescriptorWatcher is passed in which is already attached to
   // an event, then the effect is cumulative i.e. after the call |controller|
   // will watch both the previous event and the new one.
   // If an error occurs while calling this method in a cumulative fashion, the
   // event previously attached to |controller| is aborted.
@@ skipping 24 matching lines @@
   ThreadChecker watch_file_descriptor_caller_checker_;
 
   base::WeakPtrFactory<MessagePumpIOSForIO> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpIOSForIO);
 };
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_IO_IOS_H_