[ChromeDriver] Added 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..63730fd3f245cbf2c9b9d208c2da346eaaceda5b 100644
--- a/chrome/test/chromedriver/session.cc
+++ b/chrome/test/chromedriver/session.cc
@@ -65,6 +65,19 @@ Status Session::GetTargetWindow(WebView** web_view) {
   return status;
 }
 
+Status Session::OnCommand(const std::string& command_name) {
+  // Notify listeners of the command.
+  for (ScopedVector<CommandListener>::const_iterator it =
+      command_listeners_.begin();
+      it != command_listeners_.end();
+      ++it) {
+    Status status = (*it)->OnCommand(command_name);
+    if (status.IsError())
+      return status;
+  }
+  return Status(kOk);
+}
+
 void Session::SwitchToTopFrame() {
   frames.clear();
 }
@@ -82,6 +95,11 @@ 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();