Remove special frontend for callbacks with slow-mode holders.

src/stub-cache.h

 // Copyright 2012 the V8 project 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 V8_STUB_CACHE_H_
 #define V8_STUB_CACHE_H_
 
 #include "src/allocation.h"
 #include "src/arguments.h"
 #include "src/code-stubs.h"
@@ skipping 500 matching lines @@
   static const int kInterceptorArgsHolderIndex = 3;
   static const int kInterceptorArgsLength = 4;
 
  protected:
   virtual Register FrontendHeader(Register object_reg, Handle<Name> name,
                                   Label* miss);
 
   virtual void FrontendFooter(Handle<Name> name, Label* miss);
 
  private:
-  Register CallbackFrontend(Register object_reg, Handle<Name> name,
-                            Handle<Object> callback);
   Handle<Code> CompileLoadNonexistent(Handle<Name> name);
   void GenerateLoadField(Register reg,
                          FieldIndex field,
                          Representation representation);
   void GenerateLoadConstant(Handle<Object> value);
   void GenerateLoadCallback(Register reg,
                             Handle<ExecutableAccessorInfo> callback);
   void GenerateLoadCallback(const CallOptimization& call_optimization,
                             Handle<Map> receiver_map);
   void GenerateLoadInterceptor(Register holder_reg,
@@ skipping 150 matching lines @@
   Handle<JSFunction> constant_function_;
   bool is_simple_api_call_;
   Handle<FunctionTemplateInfo> expected_receiver_type_;
   Handle<CallHandlerInfo> api_call_info_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_STUB_CACHE_H_