[debug] Remove DebugInterface class

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index c8db633f7c3aa30b1b5ebd8ab8f2a60e01e7e1d3..931cc34ebb4fa50a806b17a819b400354fe25ad8 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -1836,8 +1836,8 @@ void Debug::CallEventCallback(v8::DebugEvent event,
   in_debug_event_listener_ = true;
   if (event_listener_->IsForeign()) {
     // Invoke the C debug event listener.
-    v8::DebugInterface::EventCallback callback =
-        FUNCTION_CAST<v8::DebugInterface::EventCallback>(
+    debug::DebugInterface::EventCallback callback =
+        FUNCTION_CAST<debug::DebugInterface::EventCallback>(
             Handle<Foreign>::cast(event_listener_)->foreign_address());
     EventDetailsImpl event_details(event,
                                    Handle<JSObject>::cast(exec_state),