Remove the --speech-service-key command line flag.

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index be90de9c2f93562eb893e21dd1b5d7c2b7b8c79a..2e1305db11fb03a08a9778b11f70fa324b311c04 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -828,9 +828,6 @@ const char kSitePerProcess[]                = "site-per-process";
 // TODO(gab): Get rid of this switch entirely.
 const char kSkipGpuDataLoading[]            = "skip-gpu-data-loading";
 
-// Specifies the request key for the continuous speech recognition webservice.
-const char kSpeechRecognitionWebserviceKey[] = "speech-service-key";
-
 // Specifies if the browser should start in fullscreen mode, like if the user
 // had pressed F11 right after startup.
 const char kStartFullscreen[] = "start-fullscreen";