[debugger] Remove code to predict step-in target.

src/objects.cc

 // Copyright 2013 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 1044 matching lines @@
   // that location. The best solution seems to be to break the impasse by
   // adding checks at possible recursion points. What's more, we don't put
   // this stack check behind the USE_SIMULATOR define in order to keep
   // behavior the same between hardware and simulators.
   StackLimitCheck check(isolate);
   if (check.JsHasOverflowed()) {
     isolate->StackOverflow();
     return MaybeHandle<Object>();
   }
 
-  Debug* debug = isolate->debug();
-  // Handle stepping into a getter if step into is active.
-  // TODO(rossberg): should this apply to getters that are function proxies?
-  if (debug->is_active()) debug->HandleStepIn(getter);
-
   return Execution::Call(isolate, getter, receiver, 0, NULL);
 }
 
 
 Maybe<bool> Object::SetPropertyWithDefinedSetter(Handle<Object> receiver,
                                                  Handle<JSReceiver> setter,
                                                  Handle<Object> value,
                                                  ShouldThrow should_throw) {
   Isolate* isolate = setter->GetIsolate();
 
-  Debug* debug = isolate->debug();
-  // Handle stepping into a setter if step into is active.
-  // TODO(rossberg): should this apply to getters that are function proxies?
-  if (debug->is_active()) debug->HandleStepIn(setter);
-
   Handle<Object> argv[] = { value };
   RETURN_ON_EXCEPTION_VALUE(isolate, Execution::Call(isolate, setter, receiver,
                                                      arraysize(argv), argv),
                             Nothing<bool>());
   return Just(true);
 }
 
 
 // static
 bool JSObject::AllCanRead(LookupIterator* it) {
@@ skipping 17506 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8