[Mac] Move ScopedSendingEvent from content/common/mac to base/mac.

base/mac/scoped_sending_event.mm

 // Copyright (c) 2011 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.
 
-#import "content/common/mac/scoped_sending_event.h"
+#import "base/mac/scoped_sending_event.h"
 
 #include "base/logging.h"
 
-namespace content {
+namespace base {
 namespace mac {
 
 ScopedSendingEvent::ScopedSendingEvent()
     : app_(static_cast<NSObject<CrAppControlProtocol>*>(NSApp)) {
   DCHECK([app_ conformsToProtocol:@protocol(CrAppControlProtocol)]);
   handling_ = [app_ isHandlingSendEvent];
   [app_ setHandlingSendEvent:YES];
 }
 
 ScopedSendingEvent::~ScopedSendingEvent() {
   [app_ setHandlingSendEvent:handling_];
 }
 
 }  // namespace mac
-}  // namespace content
+}  // namespace base