Fix more GC unsafe places

src/debug.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 1016 matching lines @@
 
 
 // Check whether a single break point object is triggered.
 bool Debug::CheckBreakPoint(Handle<Object> break_point_object) {
   HandleScope scope;
 
   // Ignore check if break point object is not a JSObject.
   if (!break_point_object->IsJSObject()) return true;
 
   // Get the function CheckBreakPoint (defined in debug.js).
+  Handle<String> is_break_point_triggered_symbol =
+      Factory::LookupAsciiSymbol("IsBreakPointTriggered");
   Handle<JSFunction> check_break_point =
     Handle<JSFunction>(JSFunction::cast(
-      debug_context()->global()->GetProperty(
-          *Factory::LookupAsciiSymbol("IsBreakPointTriggered"))));
+        debug_context()->global()->GetProperty(
+            *is_break_point_triggered_symbol)));
 
   // Get the break id as an object.
   Handle<Object> break_id = Factory::NewNumberFromInt(Debug::break_id());
 
   // Call HandleBreakPointx.
   bool caught_exception = false;
   const int argc = 2;
   Object** argv[argc] = {
     break_id.location(),
     reinterpret_cast<Object**>(break_point_object.location())
@@ skipping 1118 matching lines @@
   bool in_debugger = Debug::InDebugger();
 
   // Enter the debugger.
   EnterDebugger debugger;
   if (debugger.FailedToEnter()) return;
 
   // If debugging there might be script break points registered for this
   // script. Make sure that these break points are set.
 
   // Get the function UpdateScriptBreakPoints (defined in debug-debugger.js).
+  Handle<String> update_script_break_points_symbol =
+      Factory::LookupAsciiSymbol("UpdateScriptBreakPoints");
   Handle<Object> update_script_break_points =
       Handle<Object>(Debug::debug_context()->global()->GetProperty(
-          *Factory::LookupAsciiSymbol("UpdateScriptBreakPoints")));
+          *update_script_break_points_symbol));
   if (!update_script_break_points->IsJSFunction()) {
     return;
   }
   ASSERT(update_script_break_points->IsJSFunction());
 
   // Wrap the script object in a proper JS object before passing it
   // to JavaScript.
   Handle<JSValue> wrapper = GetScriptWrapper(script);
 
   // Call UpdateScriptBreakPoints expect no exceptions.
@@ skipping 864 matching lines @@
     {
       Locker locker;
       Debugger::CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal