Reland "Simplify debugger state."

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 2a41355c67231f37335d9dea138b31fa716e6162..551a04abc81fc9db6ed1050551bb5aa4fa81d097 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2169,20 +2169,18 @@ bool Genesis::InstallSpecialObjects(Handle<Context> native_context) {
 
   // Expose the debug global object in global if a name for it is specified.
   if (FLAG_expose_debug_as != NULL && strlen(FLAG_expose_debug_as) != 0) {
-    Debug* debug = isolate->debug();
     // If loading fails we just bail out without installing the
     // debugger but without tanking the whole context.
+    Debug* debug = isolate->debug();
     if (!debug->Load()) return true;
+    Handle<Context> debug_context = debug->debug_context();
     // Set the security token for the debugger context to the same as
     // the shell native context to allow calling between these (otherwise
     // exposing debug global object doesn't make much sense).
-    debug->debug_context()->set_security_token(
-        native_context->security_token());
-
+    debug_context->set_security_token(native_context->security_token());
     Handle<String> debug_string =
         factory->InternalizeUtf8String(FLAG_expose_debug_as);
-    Handle<Object> global_proxy(
-        debug->debug_context()->global_proxy(), isolate);
+    Handle<Object> global_proxy(debug_context->global_proxy(), isolate);
     RETURN_ON_EXCEPTION_VALUE(
         isolate,
         JSObject::SetLocalPropertyIgnoreAttributes(