[Mac] Ignore spell-checker exceptions.

base/mac/scoped_nsexception_enabler.h

Index: base/mac/scoped_nsexception_enabler.h
diff --git a/base/mac/scoped_nsexception_enabler.h b/base/mac/scoped_nsexception_enabler.h
index 3c16d2f5679035395dc426c879f50e5313724264..92339df31e63ae9fd361f18a024f197738ea74cc 100644
--- a/base/mac/scoped_nsexception_enabler.h
+++ b/base/mac/scoped_nsexception_enabler.h
@@ -6,6 +6,8 @@
 #define BASE_MAC_SCOPED_NSEXCEPTION_ENABLER_H_
 #pragma once
 
+#import <Foundation/Foundation.h>
+
 #include "base/base_export.h"
 #include "base/basictypes.h"
 
@@ -41,6 +43,11 @@ class BASE_EXPORT ScopedNSExceptionEnabler {
 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