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

base/native_library.h

Index: base/native_library.h
diff --git a/base/native_library.h b/base/native_library.h
index 37d72295d678509274ca81a7b384b8b220c23689..27e603ef4789cf586a9cc39c6b46594296eee6fa 100644
--- a/base/native_library.h
+++ b/base/native_library.h
@@ -37,9 +37,15 @@ 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;