WakeUp thread interrupter when isolate is made current

runtime/vm/profiler.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/utils.h"
 
 #include "vm/allocation.h"
 #include "vm/atomic.h"
 #include "vm/code_patcher.h"
 #include "vm/isolate.h"
@@ skipping 133 matching lines @@
   }
   if (!FLAG_profile) {
     return;
   }
   ASSERT(initialized_);
   IsolateProfilerData* profiler_data = isolate->profiler_data();
   if (profiler_data == NULL) {
     return;
   }
   ThreadInterrupter::Register(RecordSampleInterruptCallback, isolate);
+  ThreadInterrupter::WakeUp();
 }
 
 
 void Profiler::EndExecution(Isolate* isolate) {
   if (isolate == NULL) {
     return;
   }
   if (!FLAG_profile) {
     return;
   }
@@ skipping 1696 matching lines @@
       ProfilerDartStackWalker stackWalker(sample);
       stackWalker.walk();
     } else {
       // TODO(johnmccutchan): Support collecting only Dart frames with
       // ProfilerNativeStackWalker.
     }
   }
 }
 
 }  // namespace dart