Make Failure inherit from MaybeObject instead of Object.

src/code-stubs.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 105 matching lines @@
               new_object);
       Heap::public_set_code_stubs(*dict);
     }
     code = *new_object;
   }
 
   return Handle<Code>(code);
 }
 
 
-Object* CodeStub::TryGetCode() {
+MaybeObject* CodeStub::TryGetCode() {
   Code* code;
   if (!FindCodeInCache(&code)) {
     // Generate the new code.
     MacroAssembler masm(NULL, 256);
     GenerateCode(&masm);
 
     // Create the code object.
     CodeDesc desc;
     masm.GetCode(&desc);
 
     // Try to copy the generated code into a heap object.
     Code::Flags flags = Code::ComputeFlags(
         static_cast<Code::Kind>(GetCodeKind()),
         InLoop(),
         GetICState());
-    Object* new_object = Heap::CreateCode(desc, flags, masm.CodeObject());
-    if (new_object->IsFailure()) return new_object;
+    Object* new_object;
+    { MaybeObject* maybe_new_object =
+          Heap::CreateCode(desc, flags, masm.CodeObject());
+      if (!maybe_new_object->ToObject(&new_object)) return maybe_new_object;
+    }
     code = Code::cast(new_object);
     RecordCodeGeneration(code, &masm);
 
     if (has_custom_cache()) {
       SetCustomCache(code);
     } else {
       // Try to update the code cache but do not fail if unable.
-      new_object = Heap::code_stubs()->AtNumberPut(GetKey(), code);
-      if (!new_object->IsFailure()) {
+      MaybeObject* maybe_new_object =
+          Heap::code_stubs()->AtNumberPut(GetKey(), code);
+      if (maybe_new_object->ToObject(&new_object)) {
         Heap::public_set_code_stubs(NumberDictionary::cast(new_object));
       }
     }
   }
 
   return code;
 }
 
 
 const char* CodeStub::MajorName(CodeStub::Major major_key,
                                 bool allow_unknown_keys) {
   switch (major_key) {
 #define DEF_CASE(name) case name: return #name;
     CODE_STUB_LIST(DEF_CASE)
 #undef DEF_CASE
     default:
       if (!allow_unknown_keys) {
         UNREACHABLE();
       }
       return NULL;
   }
 }
 
 
 } }  // namespace v8::internal