Switch profiler from isolates to threads

runtime/vm/debugger.cc

Index: runtime/vm/debugger.cc
diff --git a/runtime/vm/debugger.cc b/runtime/vm/debugger.cc
index 79153f47459047bd02ee3931b40bd70b5132d88d..d0c799d75e0e068017df6cf3f1af692e012ceccc 100644
--- a/runtime/vm/debugger.cc
+++ b/runtime/vm/debugger.cc
@@ -2547,11 +2547,6 @@ void Debugger::HandleSteppingRequest(DebuggerStackTrace* stack_trace) {
       }
     }
   }
-  if (!isolate_->single_step()) {

[Ivan Posva, 2015/10/28 06:45:16]

Where is the equivalent for single step handling in this thread based version?

[Cutch, 2015/10/28 14:57:51]

I've moved this into Debugger::Pause which disables interrupts while the thread
waits for debugger commands.

-    // We are no longer single stepping, make sure that the ThreadInterrupter
-    // is awake.
-    ThreadInterrupter::WakeUp();
-  }
 }