Introduce new stepping mode to step into another frame.

src/runtime/runtime-debug.cc

 // Copyright 2014 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/v8.h"
 
 #include "src/accessors.h"
 #include "src/arguments.h"
 #include "src/debug.h"
 #include "src/deoptimizer.h"
@@ skipping 1966 matching lines @@
   if (wrapped_frame_id == 0) {
     frame_id = StackFrame::NO_ID;
   } else {
     frame_id = UnwrapFrameId(wrapped_frame_id);
   }
 
   // Get the step action and check validity.
   StepAction step_action = static_cast<StepAction>(NumberToInt32(args[1]));
   if (step_action != StepIn && step_action != StepNext &&
       step_action != StepOut && step_action != StepInMin &&
-      step_action != StepMin) {
+      step_action != StepMin && step_action != StepFrame) {
     return isolate->Throw(isolate->heap()->illegal_argument_string());
   }
 
   if (frame_id != StackFrame::NO_ID && step_action != StepNext &&
       step_action != StepMin && step_action != StepOut) {
     return isolate->ThrowIllegalOperation();
   }
 
   // Get the number of steps.
   int step_count = NumberToInt32(args[2]);
@@ skipping 723 matching lines @@
   return Smi::FromInt(isolate->debug()->is_active());
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_DebugBreakInOptimizedCode) {
   UNIMPLEMENTED();
   return NULL;
 }
 }
 }  // namespace v8::internal