Add getUserSelectedDevices to the USB extensions API.

extensions/browser/api/extensions_api_client.cc

Index: extensions/browser/api/extensions_api_client.cc
diff --git a/extensions/browser/api/extensions_api_client.cc b/extensions/browser/api/extensions_api_client.cc
index 711f6c15c4ce138b665f11a2510c5e5412aeffd2..67fd63952975034b560048c401d4322883954cbd 100644
--- a/extensions/browser/api/extensions_api_client.cc
+++ b/extensions/browser/api/extensions_api_client.cc
@@ -5,6 +5,7 @@
 #include "extensions/browser/api/extensions_api_client.h"
 
 #include "base/logging.h"
+#include "extensions/browser/api/device_permissions_prompt.h"
 #include "extensions/browser/api/web_request/web_request_event_router_delegate.h"
 #include "extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest_delegate.h"
 #include "extensions/browser/guest_view/web_view/web_view_permission_helper_delegate.h"
@@ -68,4 +69,10 @@ ExtensionsAPIClient::CreateContentRulesRegistry(
   return scoped_refptr<ContentRulesRegistry>();
 }
 
+scoped_ptr<DevicePermissionsPrompt>
+ExtensionsAPIClient::CreateDevicePermissionsPrompt(
+    content::WebContents* web_contents) const {
+  return nullptr;
+}
+
 }  // namespace extensions