Service Worker: Use more specific errors when StartWorker fails

content/browser/service_worker/embedded_worker_instance.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/service_worker/embedded_worker_instance.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind_helpers.h"
@@ skipping 336 matching lines @@
   }
   thread_id_ = thread_id;
   FOR_EACH_OBSERVER(Listener, listener_list_, OnScriptLoaded());
 }
 
 void EmbeddedWorkerInstance::OnScriptLoadFailed() {
 }
 
 void EmbeddedWorkerInstance::OnScriptEvaluated(bool success) {
   starting_phase_ = SCRIPT_EVALUATED;
+  if (start_callback_.is_null()) {
+    DVLOG(1) << "Received unexpected OnScriptEvaluated message.";
+    return;
+  }
   if (success && !start_timing_.is_null()) {
     UMA_HISTOGRAM_TIMES("EmbeddedWorkerInstance.ScriptEvaluate",
                         base::TimeTicks::Now() - start_timing_);
   }
-  DCHECK(!start_callback_.is_null());
   start_callback_.Run(success ? SERVICE_WORKER_OK
-                              : SERVICE_WORKER_ERROR_START_WORKER_FAILED);
+                              : SERVICE_WORKER_ERROR_SCRIPT_EVALUATE_FAILED);
   start_callback_.Reset();
 }
 
 void EmbeddedWorkerInstance::OnStarted() {
   // Stop is requested before OnStarted is sent back from the worker.
   if (status_ == STOPPING)
     return;
   DCHECK(status_ == STARTING);
   status_ = RUNNING;
   FOR_EACH_OBSERVER(Listener, listener_list_, OnStarted());
@@ skipping 110 matching lines @@
     case SCRIPT_EVALUATED:
       return "Script evaluated";
     case STARTING_PHASE_MAX_VALUE:
       NOTREACHED();
   }
   NOTREACHED() << phase;
   return std::string();
 }
 
 }  // namespace content