[Mac] Do not unload base::NativeLibary-ies if they contain ObjC segments.

base/native_library.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_NATIVE_LIBRARY_H_
 #define BASE_NATIVE_LIBRARY_H_
 
 // This file defines a cross-platform "NativeLibrary" type which represents
 // a loadable module.
 
@@ skipping 19 matching lines @@
 
 class FilePath;
 
 #if defined(OS_WIN)
 typedef HMODULE NativeLibrary;
 #elif defined(OS_MACOSX)
 enum NativeLibraryType {
   BUNDLE,
   DYNAMIC_LIB
 };
+enum NativeLibraryObjCStatus {
+  OBJC_UNKNOWN,
+  OBJC_PRESENT,
+  OBJC_NOT_PRESENT,
+};
 struct NativeLibraryStruct {
   NativeLibraryType type;
   CFBundleRefNum bundle_resource_ref;
+  NativeLibraryObjCStatus objc_status;
   union {
     CFBundleRef bundle;
     void* dylib;
   };
 };
 typedef NativeLibraryStruct* NativeLibrary;
 #elif defined(OS_POSIX)
 typedef void* NativeLibrary;
 #endif  // OS_*
 
@@ skipping 23 matching lines @@
 
 // Returns the full platform specific name for a native library.
 // For example:
 // "mylib" returns "mylib.dll" on Windows, "libmylib.so" on Linux,
 // "mylib.dylib" on Mac.
 BASE_EXPORT string16 GetNativeLibraryName(const string16& name);
 
 }  // namespace base
 
 #endif  // BASE_NATIVE_LIBRARY_H_