Remember when an isolate was paused and subtly display it in Obseravatory

runtime/vm/isolate.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 "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "vm/code_observers.h"
@@ skipping 643 matching lines @@
       heap_(NULL),
       object_store_(NULL),
       top_exit_frame_info_(0),
       init_callback_data_(NULL),
       environment_callback_(NULL),
       library_tag_handler_(NULL),
       api_state_(NULL),
       debugger_(NULL),
       single_step_(false),
       resume_request_(false),
+      last_resume_timestamp_(OS::GetCurrentTimeMillis()),
       has_compiled_(false),
       flags_(),
       random_(),
       simulator_(NULL),
       timer_list_(),
       deopt_id_(0),
       mutex_(new Mutex()),
       stack_limit_(0),
       saved_stack_limit_(0),
       stack_base_(0),
@@ skipping 993 matching lines @@
   jsobj.AddFixedServiceId("isolates/%" Pd "",
                           static_cast<intptr_t>(main_port()));
 
   jsobj.AddProperty("name", debugger_name());
   jsobj.AddPropertyF("number", "%" Pd "",
                      static_cast<intptr_t>(main_port()));
   if (ref) {
     return;
   }
   int64_t start_time_millis = start_time() / kMicrosecondsPerMillisecond;
-  jsobj.AddProperty64("startTime", start_time_millis);
+  jsobj.AddPropertyTimeMillis("startTime", start_time_millis);
   IsolateSpawnState* state = spawn_state();
   if (state != NULL) {
     const Object& entry = Object::Handle(this, state->ResolveFunction());
     if (!entry.IsNull() && entry.IsFunction()) {
       Function& func = Function::Handle(this);
       func ^= entry.raw();
       jsobj.AddProperty("entry", func);
     }
   }
   {
@@ skipping 474 matching lines @@
                            serialized_message_, serialized_message_len_);
 }
 
 
 void IsolateSpawnState::Cleanup() {
   SwitchIsolateScope switch_scope(I);
   Dart::ShutdownIsolate();
 }
 
 }  // namespace dart