Move some code from Runtime_GetPrototype into a new Object::GetPrototype.

src/runtime/runtime-debug.cc

 // Copyright 2014 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.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/debug/debug.h"
 #include "src/debug/debug-evaluate.h"
 #include "src/debug/debug-frames.h"
@@ skipping 1434 matching lines @@
   return *isolate->factory()->NewJSArrayWithElements(result);
 }
 
 
 // Find the effective prototype object as returned by __proto__.
 // args[0]: the object to find the prototype for.
 RUNTIME_FUNCTION(Runtime_DebugGetPrototype) {
   HandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
-  return *Object::GetPrototypeSkipHiddenPrototypes(isolate, obj);
+  return *Object::GetPrototypeWithAccess(isolate, obj);

[neis, 2015/10/13 14:55:54]

Is it correct to not do an access check here?  If not (i.e. this should be a
call to GetPrototype), then is it worth having GetPrototypeWithAccess at all? 
The only other place where it's used is in Runtime_SetPrototype, in order to
avoid two redundant checks.

[Toon Verwaest, 2015/10/14 10:56:18]

Given that the other 2 cases deal with Object.observe, it might be worthwhile to
just drop that function.

 }
 
 
 // Patches script source (should be called upon BeforeCompile event).
 RUNTIME_FUNCTION(Runtime_DebugSetScriptSource) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
 
   CONVERT_ARG_HANDLE_CHECKED(JSValue, script_wrapper, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, source, 1);
@@ skipping 248 matching lines @@
   return *isolate->factory()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_DebugBreakInOptimizedCode) {
   UNIMPLEMENTED();
   return NULL;
 }
 }  // namespace internal
 }  // namespace v8