Fix bots- set last resume timestamp when isolate is made runnable

runtime/vm/isolate.h

 // 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.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 294 matching lines @@
   // Marks all libraries as loaded.
   void DoneLoading();
 
   bool MakeRunnable();
   void Run();
 
   MessageHandler* message_handler() const { return message_handler_; }
   void set_message_handler(MessageHandler* value) { message_handler_ = value; }
 
   bool is_runnable() const { return is_runnable_; }
-  void set_is_runnable(bool value) { is_runnable_ = value; }
+  void set_is_runnable(bool value) {
+    is_runnable_ = value;
+    if (is_runnable_) {
+      set_last_resume_timestamp();
+    }
+  }
 
   IsolateSpawnState* spawn_state() const { return spawn_state_; }
   void set_spawn_state(IsolateSpawnState* value) { spawn_state_ = value; }
 
   Mutex* mutex() const { return mutex_; }
   Mutex* symbols_mutex() const { return symbols_mutex_; }
   Mutex* type_canonicalization_mutex() const {
     return type_canonicalization_mutex_;
   }
   Mutex* constant_canonicalization_mutex() const {
@@ skipping 699 matching lines @@
   intptr_t* spawn_count_;
 
   Dart_IsolateFlags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_