If user had consented for metrics reporting, send speech input request origin to the server.

chrome/browser/speech/speech_recognition_request.cc

Index: chrome/browser/speech/speech_recognition_request.cc
diff --git a/chrome/browser/speech/speech_recognition_request.cc b/chrome/browser/speech/speech_recognition_request.cc
index 1281666f3d4a9184d492a5f0bf0e9b021d77b8cb..754534aa9e5af3300720e6f10e67393289115df1 100644
--- a/chrome/browser/speech/speech_recognition_request.cc
+++ b/chrome/browser/speech/speech_recognition_request.cc
@@ -123,6 +123,7 @@ SpeechRecognitionRequest::~SpeechRecognitionRequest() {}
 bool SpeechRecognitionRequest::Send(const std::string& language,
                                     const std::string& grammar,
                                     const std::string& hardware_info,
+                                    const std::string& origin_url,
                                     const std::string& content_type,
                                     const std::string& audio_data) {
   DCHECK(!url_fetcher_.get());
@@ -161,6 +162,7 @@ bool SpeechRecognitionRequest::Send(const std::string& language,
                                         this));
   url_fetcher_->set_upload_data(content_type, audio_data);
   url_fetcher_->set_request_context(url_context_);
+  url_fetcher_->set_referrer(origin_url);
 
   // The speech recognition API does not require user identification as part
   // of requests, so we don't send cookies or auth data for these requests to