| Index: src/runtime/runtime-debug.cc | 
| diff --git a/src/runtime/runtime-debug.cc b/src/runtime/runtime-debug.cc | 
| index e01dd8797d5fb26ca7f7327e492d62f6b890b784..5baa151488f1e03cdf16026751ac31c09cd86b6d 100644 | 
| --- a/src/runtime/runtime-debug.cc | 
| +++ b/src/runtime/runtime-debug.cc | 
| @@ -2183,7 +2183,7 @@ static bool IsPositionAlignmentCodeCorrect(int alignment) { | 
| RUNTIME_FUNCTION(Runtime_GetBreakLocations) { | 
| HandleScope scope(isolate); | 
| DCHECK(args.length() == 2); | 
| - | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
| CONVERT_ARG_HANDLE_CHECKED(JSFunction, fun, 0); | 
| CONVERT_NUMBER_CHECKED(int32_t, statement_aligned_code, Int32, args[1]); | 
|  | 
| @@ -2211,6 +2211,7 @@ RUNTIME_FUNCTION(Runtime_GetBreakLocations) { | 
| RUNTIME_FUNCTION(Runtime_SetFunctionBreakPoint) { | 
| HandleScope scope(isolate); | 
| DCHECK(args.length() == 3); | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
| CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0); | 
| CONVERT_NUMBER_CHECKED(int32_t, source_position, Int32, args[1]); | 
| RUNTIME_ASSERT(source_position >= function->shared()->start_position() && | 
| @@ -2235,6 +2236,7 @@ RUNTIME_FUNCTION(Runtime_SetFunctionBreakPoint) { | 
| RUNTIME_FUNCTION(Runtime_SetScriptBreakPoint) { | 
| HandleScope scope(isolate); | 
| DCHECK(args.length() == 4); | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
| CONVERT_ARG_HANDLE_CHECKED(JSValue, wrapper, 0); | 
| CONVERT_NUMBER_CHECKED(int32_t, source_position, Int32, args[1]); | 
| RUNTIME_ASSERT(source_position >= 0); | 
| @@ -2266,6 +2268,7 @@ RUNTIME_FUNCTION(Runtime_SetScriptBreakPoint) { | 
| RUNTIME_FUNCTION(Runtime_ClearBreakPoint) { | 
| HandleScope scope(isolate); | 
| DCHECK(args.length() == 1); | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
| CONVERT_ARG_HANDLE_CHECKED(Object, break_point_object_arg, 0); | 
|  | 
| // Clear break point. | 
| @@ -2363,6 +2366,7 @@ RUNTIME_FUNCTION(Runtime_PrepareStep) { | 
| RUNTIME_FUNCTION(Runtime_ClearStepping) { | 
| HandleScope scope(isolate); | 
| DCHECK(args.length() == 0); | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
| isolate->debug()->ClearStepping(); | 
| return isolate->heap()->undefined_value(); | 
| } | 
| @@ -2709,6 +2713,7 @@ RUNTIME_FUNCTION(Runtime_DebugEvaluateGlobal) { | 
| RUNTIME_FUNCTION(Runtime_DebugGetLoadedScripts) { | 
| HandleScope scope(isolate); | 
| DCHECK(args.length() == 0); | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
|  | 
| Handle<FixedArray> instances; | 
| { | 
| @@ -2976,6 +2981,7 @@ RUNTIME_FUNCTION(Runtime_GetFunctionCodePositionFromSource) { | 
| HandleScope scope(isolate); | 
| CHECK(isolate->debug()->live_edit_enabled()); | 
| DCHECK(args.length() == 2); | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
| CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0); | 
| CONVERT_NUMBER_CHECKED(int32_t, source_position, Int32, args[1]); | 
|  | 
| @@ -3117,6 +3123,8 @@ RUNTIME_FUNCTION(Runtime_DebugCallbackSupportsStepping) { | 
| // built-in function such as Array.forEach to enable stepping into the callback. | 
| RUNTIME_FUNCTION(Runtime_DebugPrepareStepInIfStepping) { | 
| DCHECK(args.length() == 1); | 
| +  RUNTIME_ASSERT(isolate->debug()->is_active()); | 
| + | 
| Debug* debug = isolate->debug(); | 
| if (!debug->IsStepping()) return isolate->heap()->undefined_value(); | 
|  | 
|  |