Always initialize the debugger eagerly.

src/liveedit.cc

 // Copyright 2012 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 "v8.h"
 
 #include "liveedit.h"
 
 #include "code-stubs.h"
@@ skipping 1551 matching lines @@
   // Check the nature of the top frame.
   Isolate* isolate = bottom_js_frame->isolate();
   Code* pre_top_frame_code = pre_top_frame->LookupCode();
   bool frame_has_padding;
   if (pre_top_frame_code->is_inline_cache_stub() &&
       pre_top_frame_code->is_debug_stub()) {
     // OK, we can drop inline cache calls.
     *mode = Debug::FRAME_DROPPED_IN_IC_CALL;
     frame_has_padding = Debug::FramePaddingLayout::kIsSupported;
   } else if (pre_top_frame_code ==
-             isolate->debug()->debug_break_slot()) {
+             isolate->builtins()->builtin(Builtins::kSlot_DebugBreak)) {
     // OK, we can drop debug break slot.
     *mode = Debug::FRAME_DROPPED_IN_DEBUG_SLOT_CALL;
     frame_has_padding = Debug::FramePaddingLayout::kIsSupported;
   } else if (pre_top_frame_code ==
       isolate->builtins()->builtin(
           Builtins::kFrameDropper_LiveEdit)) {
     // OK, we can drop our own code.
     pre_top_frame = frames[top_frame_index - 2];
     top_frame = frames[top_frame_index - 1];
     *mode = Debug::CURRENTLY_SET_MODE;
@@ skipping 387 matching lines @@
 void LiveEditFunctionTracker::RecordRootFunctionInfo(Handle<Code> code) {
   isolate_->active_function_info_listener()->FunctionCode(code);
 }
 
 
 bool LiveEditFunctionTracker::IsActive(Isolate* isolate) {
   return isolate->active_function_info_listener() != NULL;
 }
 
 } }  // namespace v8::internal