Ignore pause on debugger statement when breakpoints are disabled

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index 1ea420fefe8e1eda7a9f3bf57fc02c13383d8e1f..23a486f26d4e65f16c270a42c56eefd2a5870252 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -2216,7 +2216,9 @@ void Debug::HandleDebugBreak() {
   // Ignore debug break during bootstrapping.
   if (isolate_->bootstrapper()->IsActive()) return;
   // Just continue if breaks are disabled.
-  if (break_disabled()) return;
+  if (break_disabled() ||
+      (!break_points_active_ && thread_local_.last_step_action_ == StepNone))

[Yang, 2016/02/12 05:56:23]

Why do we need to check last_step_action_? Stepping in V8 does not go this code
path. I think DevTools does for async stepping, as it uses debug break
interrupts to break asap when it executes in V8? Leaking that implementation
detail over to V8 sounds like a bad choice. And there is no test case for that
in V8.

Since this is only related to the debugger statement, could we simply do the
check for break_points_active_ in Runtime_HandleDebuggerStatement?

[kozy, 2016/02/12 17:22:04]

Hm ,thank you for explanation. I thought that this check will help me to don't
change behavior on paused. I'm going to review devtools async stepping
implementation.

For this patch - yes, we could. Moved check.

+    return;
   // Ignore debug break if debugger is not active.
   if (!is_active()) return;