Set up the infrastructure for Extension event metrics.

chrome/browser/speech/extension_api/tts_engine_extension_api.cc

Index: chrome/browser/speech/extension_api/tts_engine_extension_api.cc
diff --git a/chrome/browser/speech/extension_api/tts_engine_extension_api.cc b/chrome/browser/speech/extension_api/tts_engine_extension_api.cc
index 7e4071f516c0efaaf735ac804938cf68cfdfdf3b..a335de17aebe8b978086f2deacd2e7d36b142bca 100644
--- a/chrome/browser/speech/extension_api/tts_engine_extension_api.cc
+++ b/chrome/browser/speech/extension_api/tts_engine_extension_api.cc
@@ -194,7 +194,7 @@ void TtsExtensionEngine::Speak(Utterance* utterance,
   base::JSONWriter::Write(*args, &json);
 
   scoped_ptr<extensions::Event> event(new extensions::Event(
-      tts_engine_events::kOnSpeak, args.Pass()));
+      extensions::events::UNKNOWN, tts_engine_events::kOnSpeak, args.Pass()));
   Profile* profile = Profile::FromBrowserContext(utterance->browser_context());
   event->restrict_to_browser_context = profile;
   EventRouter::Get(profile)
@@ -204,7 +204,7 @@ void TtsExtensionEngine::Speak(Utterance* utterance,
 void TtsExtensionEngine::Stop(Utterance* utterance) {
   scoped_ptr<base::ListValue> args(new base::ListValue());
   scoped_ptr<extensions::Event> event(new extensions::Event(
-      tts_engine_events::kOnStop, args.Pass()));
+      extensions::events::UNKNOWN, tts_engine_events::kOnStop, args.Pass()));
   Profile* profile = Profile::FromBrowserContext(utterance->browser_context());
   event->restrict_to_browser_context = profile;
   EventRouter::Get(profile)
@@ -214,7 +214,7 @@ void TtsExtensionEngine::Stop(Utterance* utterance) {
 void TtsExtensionEngine::Pause(Utterance* utterance) {
   scoped_ptr<base::ListValue> args(new base::ListValue());
   scoped_ptr<extensions::Event> event(new extensions::Event(
-      tts_engine_events::kOnPause, args.Pass()));
+      extensions::events::UNKNOWN, tts_engine_events::kOnPause, args.Pass()));
   Profile* profile = Profile::FromBrowserContext(utterance->browser_context());
   event->restrict_to_browser_context = profile;
   EventRouter* event_router = EventRouter::Get(profile);
@@ -226,7 +226,7 @@ void TtsExtensionEngine::Pause(Utterance* utterance) {
 void TtsExtensionEngine::Resume(Utterance* utterance) {
   scoped_ptr<base::ListValue> args(new base::ListValue());
   scoped_ptr<extensions::Event> event(new extensions::Event(
-      tts_engine_events::kOnResume, args.Pass()));
+      extensions::events::UNKNOWN, tts_engine_events::kOnResume, args.Pass()));
   Profile* profile = Profile::FromBrowserContext(utterance->browser_context());
   event->restrict_to_browser_context = profile;
   EventRouter* event_router = EventRouter::Get(profile);