[Mac] Ignore spell-checker exceptions.

base/mac/scoped_nsexception_enabler.h

 // 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.
 
 #ifndef BASE_MAC_SCOPED_NSEXCEPTION_ENABLER_H_
 #define BASE_MAC_SCOPED_NSEXCEPTION_ENABLER_H_
 #pragma once
 
+#import <Foundation/Foundation.h>
+
 #include "base/base_export.h"
 #include "base/basictypes.h"
 
 namespace base {
 namespace mac {
 
 // BrowserCrApplication attempts to restrict throwing of NSExceptions
 // because they interact badly with C++ scoping rules.  Unfortunately,
 // there are some cases where exceptions must be supported, such as
 // when third-party printer drivers are used.  These helpers can be
@@ skipping 15 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(ScopedNSExceptionEnabler);
 };
 
 // Access the exception setting for the current thread.  This is for
 // the support code in BrowserCrApplication, other code should use
 // the scoper.
 BASE_EXPORT bool GetNSExceptionsAllowed();
 BASE_EXPORT void SetNSExceptionsAllowed(bool allowed);
 
+// Executes [target performSelector:sel] with fatal-exceptions turned
+// off, and returns the result.  If an exception is thrown during the
+// perform, nil is returned.
+BASE_EXPORT id PerformSelectorIgnoringExceptions(NSObject* target, SEL sel);
+
 }  // namespace mac
 }  // namespace base
 
 #endif  // BASE_MAC_SCOPED_NSEXCEPTION_ENABLER_H_