[debugger] expose side-effect free evaluate to inspector.

src/debug/debug-evaluate.cc

Index: src/debug/debug-evaluate.cc
diff --git a/src/debug/debug-evaluate.cc b/src/debug/debug-evaluate.cc
index b36d8a21abc873419b4e33f5285aceef1500619d..e6c6a42703cb1317991031c0d83af6889a375ee0 100644
--- a/src/debug/debug-evaluate.cc
+++ b/src/debug/debug-evaluate.cc
@@ -41,13 +41,14 @@ MaybeHandle<Object> DebugEvaluate::Global(Isolate* isolate,
   Handle<Context> context = isolate->native_context();
   Handle<JSObject> receiver(context->global_proxy());
   Handle<SharedFunctionInfo> outer_info(context->closure()->shared(), isolate);
-  return Evaluate(isolate, outer_info, context, receiver, source);
+  return Evaluate(isolate, outer_info, context, receiver, source, true);
 }
 
 MaybeHandle<Object> DebugEvaluate::Local(Isolate* isolate,
                                          StackFrame::Id frame_id,
                                          int inlined_jsframe_index,
-                                         Handle<String> source) {
+                                         Handle<String> source,
+                                         bool allow_side_effects) {
   // Handle the processing of break.
   DisableBreak disable_break_scope(isolate->debug());
 
@@ -74,8 +75,9 @@ MaybeHandle<Object> DebugEvaluate::Local(Isolate* isolate,
 
   Handle<Context> context = context_builder.evaluation_context();
   Handle<JSObject> receiver(context->global_proxy());
-  MaybeHandle<Object> maybe_result = Evaluate(
-      isolate, context_builder.outer_info(), context, receiver, source);
+  MaybeHandle<Object> maybe_result =
+      Evaluate(isolate, context_builder.outer_info(), context, receiver, source,
+               allow_side_effects);
   if (!maybe_result.is_null()) context_builder.UpdateValues();
   return maybe_result;
 }
@@ -84,7 +86,8 @@ MaybeHandle<Object> DebugEvaluate::Local(Isolate* isolate,
 // Compile and evaluate source for the given context.
 MaybeHandle<Object> DebugEvaluate::Evaluate(
     Isolate* isolate, Handle<SharedFunctionInfo> outer_info,
-    Handle<Context> context, Handle<Object> receiver, Handle<String> source) {
+    Handle<Context> context, Handle<Object> receiver, Handle<String> source,
+    bool allow_side_effects) {
   Handle<JSFunction> eval_fun;
   ASSIGN_RETURN_ON_EXCEPTION(
       isolate, eval_fun,
@@ -95,8 +98,7 @@ MaybeHandle<Object> DebugEvaluate::Evaluate(
 
   Handle<Object> result;
   {
-    NoSideEffectScope no_side_effect(isolate,
-                                     FLAG_side_effect_free_debug_evaluate);
+    NoSideEffectScope no_side_effect(isolate, !allow_side_effects);
     ASSIGN_RETURN_ON_EXCEPTION(
         isolate, result, Execution::Call(isolate, eval_fun, receiver, 0, NULL),
         Object);