Disable RTTI and C++ exceptions

chrome/browser/cocoa/nsimage_cache.mm

 // Copyright (c) 2009 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.
 
 #include "chrome/browser/cocoa/nsimage_cache.h"
 
 #include "base/logging.h"
 #include "base/mac_util.h"
 
+// When C++ exceptions are disabled, the C++ library defines |try| and
+// |catch| so as to allow exception-expecting C++ code to build properly when
+// language support for exceptions is not present.  These macros interfere
+// with the use of |@try| and |@catch| in Objective-C files such as this one.
+// Undefine these macros here, after everything has been #included, since
+// there will be no C++ uses and only Objective-C uses from this point on.
+#undef try
+#undef catch
+
 namespace nsimage_cache {
 
 static NSMutableDictionary *image_cache = nil;
 
 NSImage *ImageNamed(NSString *name) {
   DCHECK(name);
 
   // NOTE: to make this thread safe, we'd have to sync on the cache and
   // also force all the bundle calls on the main thread.
 
@@ skipping 26 matching lines @@
   // TODO: if we ever limit the cache size, this should retain & autorelease
   // the image.
   return result;
 }
 
 void Clear(void) {
   // NOTE: to make this thread safe, we'd have to sync on the cache.
   [image_cache removeAllObjects];
 }
 
-}  // nsimage_cache
+}  // namespace nsimage_cache