Refactor extension event distribution to use Values instead of JSON strings.

chrome/browser/speech/speech_input_extension_manager.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/speech_input_extension_manager.h"
 
 #include "base/bind.h"
 #include "base/json/json_writer.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
@@ skipping 266 matching lines @@
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
       base::Bind(&SpeechInputExtensionManager::SetRecognitionResultOnUIThread,
       this, result, extension_id));
 }
 
 void SpeechInputExtensionManager::SetRecognitionResultOnUIThread(
     const content::SpeechRecognitionResult& result,
     const std::string& extension_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* js_event = new DictionaryValue();
-  args.Append(js_event);
+  args->Append(js_event);
 
   ListValue* js_hypothesis_array = new ListValue();
   js_event->Set(kHypothesesKey, js_hypothesis_array);
 
   for (size_t i = 0; i < result.hypotheses.size(); ++i) {
     const SpeechRecognitionHypothesis& hypothesis = result.hypotheses[i];
 
     DictionaryValue* js_hypothesis_object = new DictionaryValue();
     js_hypothesis_array->Append(js_hypothesis_object);
 
     js_hypothesis_object->SetString(kUtteranceKey,
         UTF16ToUTF8(hypothesis.utterance));
     js_hypothesis_object->SetDouble(kConfidenceKey,
         hypothesis.confidence);
   }
 
-  std::string json_args;
-  base::JSONWriter::Write(&args, &json_args);
-  VLOG(1) << "Results: " << json_args;
-  DispatchEventToExtension(extension_id, kOnResultEvent, json_args);
+  DispatchEventToExtension(extension_id, kOnResultEvent, args.Pass());
 }
 
 void SpeechInputExtensionManager::OnRecognitionStart(int session_id) {
   DCHECK_EQ(session_id, speech_recognition_session_id_);
 }
 
 void SpeechInputExtensionManager::OnAudioStart(int session_id) {
   VLOG(1) << "OnAudioStart";
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK_EQ(session_id, speech_recognition_session_id_);
@@ skipping 107 matching lines @@
 void SpeechInputExtensionManager::OnEnvironmentEstimationComplete(
     int session_id) {
   DCHECK_EQ(session_id, speech_recognition_session_id_);
 }
 
 void SpeechInputExtensionManager::OnSoundStart(int session_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK_EQ(session_id, speech_recognition_session_id_);
   VLOG(1) << "OnSoundStart";
 
-  std::string json_args;
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
       base::Bind(&SpeechInputExtensionManager::DispatchEventToExtension,
       this, extension_id_in_use_, std::string(kOnSoundStartEvent),
-      json_args));
+      Passed(scoped_ptr<ListValue>(new ListValue()))));
 }
 
 void SpeechInputExtensionManager::OnSoundEnd(int session_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   VLOG(1) << "OnSoundEnd";
 
-  std::string json_args;
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
       base::Bind(&SpeechInputExtensionManager::DispatchEventToExtension,
       this, extension_id_in_use_, std::string(kOnSoundEndEvent),
-      json_args));
+      Passed(scoped_ptr<ListValue>(new ListValue()))));
 }
 
 void SpeechInputExtensionManager::DispatchEventToExtension(
     const std::string& extension_id, const std::string& event,
-    const std::string& json_args) {
+    scoped_ptr<ListValue> event_args) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   base::AutoLock auto_lock(state_lock_);
   if (state_ == kShutdown)
     return;
 
   if (profile_ && profile_->GetExtensionEventRouter()) {
-    std::string final_args;
-    if (json_args.empty()) {
-      ListValue args;
-      base::JSONWriter::Write(&args, &final_args);
-    } else {
-      final_args = json_args;
-    }
-
     profile_->GetExtensionEventRouter()->DispatchEventToExtension(
-        extension_id, event, final_args, profile_, GURL());
+        extension_id, event, event_args.Pass(), profile_, GURL());
   }
 }
 
 void SpeechInputExtensionManager::DispatchError(
     const std::string& error, bool dispatch_event) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   std::string extension_id;
   {
     base::AutoLock auto_lock(state_lock_);
     if (state_ == kShutdown)
       return;
 
     extension_id = extension_id_in_use_;
     ResetToIdleState();
 
     // Will set the error property in the ongoing extension function calls.
     ExtensionError details(extension_id, error);
     content::NotificationService::current()->Notify(
         chrome::NOTIFICATION_EXTENSION_SPEECH_INPUT_FAILED,
         content::Source<Profile>(profile_),
         content::Details<ExtensionError>(&details));
   }
 
   // Used for errors that are also reported via the onError event.
   if (dispatch_event) {
-    ListValue args;
+    scoped_ptr<ListValue> args(new ListValue());
     DictionaryValue* js_error = new DictionaryValue();
-    args.Append(js_error);
+    args->Append(js_error);
     js_error->SetString(kErrorCodeKey, error);
-    std::string json_args;
-    base::JSONWriter::Write(&args, &json_args);
-    DispatchEventToExtension(extension_id,
-        kOnErrorEvent, json_args);
+    DispatchEventToExtension(extension_id, kOnErrorEvent, args.Pass());
   }
 }
 
 bool SpeechInputExtensionManager::Start(
     const std::string& extension_id, const std::string& language,
     const std::string& grammar, bool filter_profanities, std::string* error) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(error);
   VLOG(1) << "Requesting start (UI thread)";
 
@@ skipping 247 matching lines @@
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_EXTENSION_SPEECH_INPUT_RECORDING_STOPPED,
       // Guarded by the state_ == kShutdown check.
       content::Source<Profile>(profile_),
       content::Details<std::string>(&extension_id));
 }
 
 void SpeechInputExtensionManager::OnAudioLevelsChange(int session_id,
                                                       float volume,
                                                       float noise_volume) {}