[ChromeDriver] Subscribe PerformanceLogger to CommandListener interface

chrome/test/chromedriver/session.cc

Index: chrome/test/chromedriver/session.cc
diff --git a/chrome/test/chromedriver/session.cc b/chrome/test/chromedriver/session.cc
index d46918e0d0f0d6d6b0529ad87f6edf8aab11012d..a986ad2b8edd0a21b5c869733417cace688783a1 100644
--- a/chrome/test/chromedriver/session.cc
+++ b/chrome/test/chromedriver/session.cc
@@ -82,6 +82,11 @@ void Session::SwitchToSubFrame(const std::string& frame_id,
   frames.push_back(FrameInfo(parent_frame_id, frame_id, chromedriver_frame_id));
 }
 
+void Session::AddListener(CommandListener* listener) {
+  CHECK(listener);
+  command_listeners.push_back(listener);
+}
+
 std::string Session::GetCurrentFrameId() const {
   if (frames.empty())
     return std::string();