Fix crash caused when speech is generated at Chrome OS startup before ExtensionService is initializ…

chrome/browser/speech/extension_api/tts_engine_extension_api.cc

 // Copyright (c) 2012 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 "chrome/browser/speech/extension_api/tts_engine_extension_api.h"
 
 #include <string>
 
 #include "base/json/json_writer.h"
 #include "base/values.h"
@@ skipping 81 matching lines @@
 bool GetMatchingExtensionVoice(
     Utterance* utterance,
     const Extension** matching_extension,
     size_t* voice_index) {
   // This will only happen during unit testing. Otherwise, an utterance
   // will always have an associated profile.
   if (!utterance->profile())
     return false;
 
   ExtensionService* service = utterance->profile()->GetExtensionService();
-  DCHECK(service);
+
+  // If speech is generated when Chrome OS first starts up, it's possible
+  // the extension service isn't even available.
+  if (!service)
+    return false;
+
   extensions::EventRouter* event_router =
       utterance->profile()->GetExtensionEventRouter();
   DCHECK(event_router);
 
   *matching_extension = NULL;
   *voice_index = -1;
   const ExtensionSet* extensions = service->extensions();
   ExtensionSet::const_iterator iter;
 
   // Make two passes: the first time, do strict language matching
@@ skipping 169 matching lines @@
     std::string error_message;
     event->GetString(constants::kErrorMessageKey, &error_message);
     controller->OnTtsEvent(
         utterance_id, TTS_EVENT_ERROR, char_index, error_message);
   } else {
     EXTENSION_FUNCTION_VALIDATE(false);
   }
 
   return true;
 }