Introduce SharedFunctionInfo::Iterator and Script::Iterator.

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 1584 matching lines @@
 // for the requested break point. For lazily compiled functions several heap
 // traversals might be required rendering this operation as a rather slow
 // operation. However for setting break points which is normally done through
 // some kind of user interaction the performance is not crucial.
 RUNTIME_FUNCTION(Runtime_GetScript) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(String, script_name, 0);
 
   Handle<Script> found;
-  Heap* heap = isolate->heap();
   {
-    HeapIterator iterator(heap);
-    HeapObject* obj = NULL;
-    while ((obj = iterator.next()) != NULL) {
-      if (!obj->IsScript()) continue;
-      Script* script = Script::cast(obj);
+    Script::Iterator iterator(isolate);
+    Script* script = NULL;
+    while ((script = iterator.Next()) != NULL) {
       if (!script->name()->IsString()) continue;
       String* name = String::cast(script->name());
       if (name->Equals(*script_name)) {
         found = Handle<Script>(script, isolate);
         break;
       }
     }
   }
 
-  if (found.is_null()) return heap->undefined_value();
+  if (found.is_null()) return isolate->heap()->undefined_value();
   return *Script::GetWrapper(found);
 }
 
 
 // Check whether debugger is about to step into the callback that is passed
 // to a built-in function such as Array.forEach.
 RUNTIME_FUNCTION(Runtime_DebugCallbackSupportsStepping) {
   DCHECK(args.length() == 1);
   Debug* debug = isolate->debug();
   if (!debug->is_active() || !debug->IsStepping() ||
@@ skipping 90 matching lines @@
   return *isolate->factory()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_DebugBreakInOptimizedCode) {
   UNIMPLEMENTED();
   return NULL;
 }
 }  // namespace internal
 }  // namespace v8