2nd attempt at adding streamListen/streamCancel to the service protocol.

runtime/vm/service_event.cc

 // Copyright (c) 2015, 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 "vm/service_event.h"
 
 namespace dart {
 
 // Translate from the legacy DebugEvent to a ServiceEvent.
 static ServiceEvent::EventType TranslateEventType(
@@ skipping 66 matching lines @@
     case kBreakpointAdded:
       return "BreakpointAdded";
     case kBreakpointResolved:
       return "BreakpointResolved";
     case kBreakpointRemoved:
       return "BreakpointRemoved";
     case kGC:
       return "GC";  // TODO(koda): Change to GarbageCollected.
     case kInspect:
       return "Inspect";
+    case kIllegal:
+      return "Illegal";
     default:
       UNREACHABLE();
       return "Unknown";
   }
 }
 
 
+const char* ServiceEvent::stream_id() const {
+  switch (type()) {
+    case kIsolateStart:
+    case kIsolateExit:
+    case kIsolateUpdate:
+      return "Isolate";
+
+    case kPauseStart:
+    case kPauseExit:
+    case kPauseBreakpoint:
+    case kPauseInterrupted:
+    case kPauseException:
+    case kResume:
+    case kBreakpointAdded:
+    case kBreakpointResolved:
+    case kBreakpointRemoved:
+    case kInspect:
+      return "Debug";
+
+    case kGC:
+      return "GC";
+
+    default:
+      UNREACHABLE();
+      return NULL;
+  }
+}
+
+
 void ServiceEvent::PrintJSON(JSONStream* js) const {
   JSONObject jsobj(js);
   jsobj.AddProperty("type", "Event");
   jsobj.AddProperty("kind", EventTypeToCString(type()));
   jsobj.AddProperty("isolate", isolate());
   if (breakpoint() != NULL) {
     jsobj.AddProperty("breakpoint", breakpoint());
   }
   if (top_frame() != NULL) {
     JSONObject jsFrame(&jsobj, "topFrame");
     top_frame()->PrintToJSONObject(&jsFrame);
     intptr_t index = 0;  // Avoid ambiguity in call to AddProperty.
     jsFrame.AddProperty("index", index);
   }
   if (exception() != NULL) {
     jsobj.AddProperty("exception", *(exception()));
   }
   if (inspectee() != NULL) {
     jsobj.AddProperty("inspectee", *(inspectee()));
   }
   if (gc_stats() != NULL) {
     jsobj.AddProperty("reason", Heap::GCReasonToString(gc_stats()->reason_));
     isolate()->heap()->PrintToJSONObject(Heap::kNew, &jsobj);
     isolate()->heap()->PrintToJSONObject(Heap::kOld, &jsobj);
   }
 }
 
 }  // namespace dart