Adds a way to specify test data files for unittests.

base/base_paths_mac.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.
 
 #include "base/base_paths_mac.h"
 
 #include <dlfcn.h>
 #import <Foundation/Foundation.h>
 #include <mach-o/dyld.h>
 
@@ skipping 50 matching lines @@
       return base::mac::GetUserDirectory(NSCachesDirectory, result);
     case base::DIR_APP_DATA:
       return base::mac::GetUserDirectory(NSApplicationSupportDirectory, result);
     case base::DIR_SOURCE_ROOT: {
       // Go through PathService to catch overrides.
       if (!PathService::Get(base::FILE_EXE, result))
         return false;
 
       // Start with the executable's directory.
       *result = result->DirName();
+
+#if !defined(OS_IOS)
       if (base::mac::AmIBundled()) {
         // The bundled app executables (Chromium, TestShell, etc) live five
         // levels down, eg:
         // src/xcodebuild/{Debug|Release}/Chromium.app/Contents/MacOS/Chromium
         *result = result->DirName().DirName().DirName().DirName().DirName();
       } else {
         // Unit tests execute two levels deep from the source root, eg:
         // src/xcodebuild/{Debug|Release}/base_unittests
         *result = result->DirName().DirName();
       }
+#endif
       return true;
     }
     default:
       return false;
   }
 }
 
 }  // namespace base