Make the Isolate parameter mandatory for internal HandleScopes.

src/debug.cc

Index: src/debug.cc
diff --git a/src/debug.cc b/src/debug.cc
index 05050d1aa2f55a403a11d3cec533f34243835d26..587bade70492007724df177d1577a3136c2e1668 100644
--- a/src/debug.cc
+++ b/src/debug.cc
@@ -389,8 +389,8 @@ void BreakLocationIterator::ClearDebugBreak() {
 }
 
 
-void BreakLocationIterator::PrepareStepIn() {
-  HandleScope scope;
+void BreakLocationIterator::PrepareStepIn(Isolate* isolate) {
+  HandleScope scope(isolate);
 
   // Step in can only be prepared if currently positioned on an IC call,
   // construct call or CallFunction stub call.
@@ -827,7 +827,6 @@ bool Debug::Load() {
   HandleScope scope(isolate_);
   Handle<Context> context =
       isolate_->bootstrapper()->CreateEnvironment(
-          isolate_,
           Handle<Object>::null(),
           v8::Handle<ObjectTemplate>(),
           NULL);
@@ -1547,7 +1546,7 @@ void Debug::PrepareStep(StepAction step_action, int step_count) {
     }
 
     // Step in or Step in min
-    it.PrepareStepIn();
+    it.PrepareStepIn(isolate_);
     ActivateStepIn(frame);
   }
 }
@@ -1704,9 +1703,10 @@ void Debug::HandleStepIn(Handle<JSFunction> function,
                          Handle<Object> holder,
                          Address fp,
                          bool is_constructor) {
+  Isolate* isolate = function->GetIsolate();
   // If the frame pointer is not supplied by the caller find it.
   if (fp == 0) {
-    StackFrameIterator it;
+    StackFrameIterator it(isolate);
     it.Advance();
     // For constructor functions skip another frame.
     if (is_constructor) {
@@ -1725,9 +1725,9 @@ void Debug::HandleStepIn(Handle<JSFunction> function,
     } else if (!function->IsBuiltin()) {
       // Don't allow step into functions in the native context.
       if (function->shared()->code() ==
-          Isolate::Current()->builtins()->builtin(Builtins::kFunctionApply) ||
+          isolate->builtins()->builtin(Builtins::kFunctionApply) ||
           function->shared()->code() ==
-          Isolate::Current()->builtins()->builtin(Builtins::kFunctionCall)) {
+          isolate->builtins()->builtin(Builtins::kFunctionCall)) {
         // Handle function.apply and function.call separately to flood the
         // function to be called and not the code for Builtins::FunctionApply or
         // Builtins::FunctionCall. The receiver of call/apply is the target