Adds HotwordPrivate API for integrating the hotword feature to AppLauncher

chrome/browser/search/hotword_service.cc

Index: chrome/browser/search/hotword_service.cc
diff --git a/chrome/browser/search/hotword_service.cc b/chrome/browser/search/hotword_service.cc
index 86dfc68be170775d0dbb83da29fd69911fa476a4..69366717d4033b22db897fdaed2de5ac042d4389 100644
--- a/chrome/browser/search/hotword_service.cc
+++ b/chrome/browser/search/hotword_service.cc
@@ -20,6 +20,19 @@
 #include "extensions/common/extension.h"
 #include "ui/base/l10n/l10n_util.h"
 
+// The whole file relies on the extension systems but this file is built on
+// some non-extension supported platforms and including an API header will cause
+// a compile error since it depends on header files generated by .idl.
+// TODO(mukai): clean up file dependencies and remove this clause.
+#if defined(ENABLE_EXTENSIONS)
+#include "chrome/browser/extensions/api/hotword_private/hotword_private_api.h"
+#endif
+
+#if defined(ENABLE_EXTENSIONS)
+using extensions::BrowserContextKeyedAPIFactory;
+using extensions::HotwordPrivateEventService;
+#endif
+
 namespace {
 const int kMaxTimesToShowOptInPopup = 10;
 
@@ -122,7 +135,8 @@ bool HotwordService::DoesHotwordSupportLanguage(Profile* profile) {
 }
 
 HotwordService::HotwordService(Profile* profile)
-    : profile_(profile) {
+    : profile_(profile),
+      client_(NULL) {
   // This will be called during profile initialization which is a good time
   // to check the user's hotword state.
   HotwordEnabled enabled_state = UNSET;
@@ -275,3 +289,32 @@ void HotwordService::OnHotwordSearchEnabledChanged(
   else
     DisableHotwordExtension(extension_service);
 }
+
+void HotwordService::RequestHotwordSession(HotwordClient* client) {
+#if defined(ENABLE_EXTENSIONS)
+  if (!IsServiceAvailable() || client_)
+    return;
+
+  client_ = client;
+
+  HotwordPrivateEventService* event_service =
+      BrowserContextKeyedAPIFactory<HotwordPrivateEventService>::Get(profile_);
+  if (event_service)
+    event_service->OnHotwordSessionRequested();
+#endif
+}
+
+void HotwordService::StopHotwordSession(HotwordClient* client) {
+#if defined(ENABLE_EXTENSIONS)
+  if (!IsServiceAvailable())
+    return;
+
+  DCHECK(client_ == client);
+
+  client_ = NULL;
+  HotwordPrivateEventService* event_service =
+      BrowserContextKeyedAPIFactory<HotwordPrivateEventService>::Get(profile_);
+  if (event_service)
+    event_service->OnHotwordSessionStopped();
+#endif
+}