Add new hotword extension for built-in hotword triggering.

chrome/browser/extensions/external_component_loader.cc

Index: chrome/browser/extensions/external_component_loader.cc
diff --git a/chrome/browser/extensions/external_component_loader.cc b/chrome/browser/extensions/external_component_loader.cc
index 462ea8b6f37860f382984d1ba5639a5c3725a3d8..efed6431df1f19525f7f743f17c88e42f3ca4c96 100644
--- a/chrome/browser/extensions/external_component_loader.cc
+++ b/chrome/browser/extensions/external_component_loader.cc
@@ -4,9 +4,11 @@
 
 #include "chrome/browser/extensions/external_component_loader.h"
 
+#include "base/command_line.h"
 #include "chrome/browser/bookmarks/enhanced_bookmarks_features.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "components/signin/core/browser/signin_manager.h"
 
@@ -41,8 +43,13 @@ void ExternalComponentLoader::StartLoading() {
 #if defined(ENABLE_EXTENSIONS)
   if (HotwordServiceFactory::IsHotwordAllowed(profile_)) {
     std::string hotwordId = extension_misc::kHotwordExtensionId;
-    prefs_->SetString(hotwordId + ".external_update_url",
-                      extension_urls::GetWebstoreUpdateUrl().spec());
+    CommandLine* command_line = CommandLine::ForCurrentProcess();
+    // TODO(amistry): Load the hotword shared module when enabling built-in
+    // hotword detection.
+    if (!command_line->HasSwitch(switches::kEnableBuiltInHotword)) {
+      prefs_->SetString(hotwordId + ".external_update_url",
+                        extension_urls::GetWebstoreUpdateUrl().spec());
+    }
   }
 #endif