Extensions: Add missing SendResponse to API call.

GetDevicesWithServiceName was missing a SendResponse when there were no
bluetooth devices known to the system.

TEST=manually via my demo app
BUG=119473


Review URL: http://codereview.chromium.org/10228006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133960 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/extensions/api/bluetooth/bluetooth_api.cc

@@ -128,9 +128,10 @@ bool BluetoothGetDevicesWithServiceNameFunction::RunImpl() {
     callbacks_pending_++;
   }
 
-  if (callbacks_pending_) {
+  if (callbacks_pending_)
     AddRef();  // Released in AddDeviceIfTrue when callbacks_pending_ == 0
-  }
+  else
+    SendResponse(true);
 
   return true;
 }