Speech refactoring: Reimplemented SpeechRecognitionManagerImpl as a FSM. (CL1.7)

content/browser/speech/google_one_shot_remote_engine.cc

Index: content/browser/speech/google_one_shot_remote_engine.cc
diff --git a/content/browser/speech/google_one_shot_remote_engine.cc b/content/browser/speech/google_one_shot_remote_engine.cc
index 452a34a9004ec13439814185552709119cf79706..539983a7c01ccb57e8d37d8d5542b901698d4fca 100644
--- a/content/browser/speech/google_one_shot_remote_engine.cc
+++ b/content/browser/speech/google_one_shot_remote_engine.cc
@@ -166,7 +166,8 @@ GoogleOneShotRemoteEngineConfig::~GoogleOneShotRemoteEngineConfig() {}
 
 GoogleOneShotRemoteEngine::GoogleOneShotRemoteEngine(
     net::URLRequestContextGetter* context)
-    : url_context_(context) {
+    : url_context_(context),
+      url_fetcher_destroyed_(false) {
 }
 
 GoogleOneShotRemoteEngine::~GoogleOneShotRemoteEngine() {}
@@ -178,7 +179,7 @@ void GoogleOneShotRemoteEngine::SetConfig(
 
 void GoogleOneShotRemoteEngine::StartRecognition() {
   DCHECK(delegate());
-  DCHECK(!url_fetcher_.get());
+  DCHECK(!url_fetcher_.get() || url_fetcher_destroyed_);
   std::string lang_param = config_.language;
 
   if (lang_param.empty() && url_context_) {
@@ -229,15 +230,31 @@ void GoogleOneShotRemoteEngine::StartRecognition() {
   url_fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES |
                              net::LOAD_DO_NOT_SEND_COOKIES |
                              net::LOAD_DO_NOT_SEND_AUTH_DATA);
+  url_fetcher_destroyed_ = false;
   url_fetcher_->Start();
 }
 
 void GoogleOneShotRemoteEngine::EndRecognition() {
-  url_fetcher_.reset();
+  // TODO(primiano) URLFetcher(Core) seems to be currently broken. In particular
+  // I am experiencing a failure in the case of a recognition suddenly aborted,
+  // with a DCHECK in content::URLFetcherCore::CompleteAddingUploadDataChunk().
+  // What happens is that this method (thus the url_fetcher dtor) might be
+  // called immediately after an AppendChunkToUpload. AppendChunkToUpload is
+  // not executed synchronously (inside URLFetcher) but defers its work to a
+  // posted task. However, it seems to me that the posted routine
+  // (CompleteAddingUploadDataChunk) does not take into account the corner case
+  // in which the URLFetcher is destructed in the meanwhile (which in turn
+  // causes a Stop() call on URLFetcherCore)
+  // Therefore I am currently commenting the .reset() call and adding the
+  // url_fetcher_destroyed_ workaround (read hack). This should not cause any
+  // memory leak due to the scoped_ptr smart pointer.
+
+  // url_fetcher_.reset();
+  url_fetcher_destroyed_ = true;
 }
 
 void GoogleOneShotRemoteEngine::TakeAudioChunk(const AudioChunk& data) {
-  DCHECK(url_fetcher_.get());
+  DCHECK(url_fetcher_.get() && !url_fetcher_destroyed_);
   DCHECK(encoder_.get());
   DCHECK_EQ(data.bytes_per_sample(), config_.audio_num_bits_per_sample / 8);
   encoder_->Encode(data);
@@ -246,7 +263,7 @@ void GoogleOneShotRemoteEngine::TakeAudioChunk(const AudioChunk& data) {
 }
 
 void GoogleOneShotRemoteEngine::AudioChunksEnded() {
-  DCHECK(url_fetcher_.get());
+  DCHECK(url_fetcher_.get() && !url_fetcher_destroyed_);
   DCHECK(encoder_.get());
 
   // UploadAudioChunk requires a non-empty final buffer. So we encode a packet
@@ -269,6 +286,8 @@ void GoogleOneShotRemoteEngine::AudioChunksEnded() {
 
 void GoogleOneShotRemoteEngine::OnURLFetchComplete(
     const content::URLFetcher* source) {
+  if (url_fetcher_destroyed_)
+    return;
   DCHECK_EQ(url_fetcher_.get(), source);
   SpeechRecognitionResult result;
   SpeechRecognitionError error(content::SPEECH_RECOGNITION_ERROR_NETWORK);
@@ -291,7 +310,7 @@ void GoogleOneShotRemoteEngine::OnURLFetchComplete(
 }
 
 bool GoogleOneShotRemoteEngine::IsRecognitionPending() const {
-  return url_fetcher_ != NULL;
+  return url_fetcher_ != NULL && !url_fetcher_destroyed_;
 }
 
 int GoogleOneShotRemoteEngine::GetDesiredAudioChunkDurationMs() const {