cros: Don't send duplicate UserSession mojo messages to ash

chrome/browser/ui/ash/session_controller_client.cc

Index: chrome/browser/ui/ash/session_controller_client.cc
diff --git a/chrome/browser/ui/ash/session_controller_client.cc b/chrome/browser/ui/ash/session_controller_client.cc
index 25379e48be0f18e85fb6e4377845dd567971a030..ff819dc8a94bc93b23117a5b7598fd23929f1eaa 100644
--- a/chrome/browser/ui/ash/session_controller_client.cc
+++ b/chrome/browser/ui/ash/session_controller_client.cc
@@ -392,10 +392,10 @@ void SessionControllerClient::SendUserSession(const User& user) {
   if (!user_session)
     return;
 
-  // TODO(jamescook): Only send if it changed. This will require an Equals()
-  // method for gfx::ImageSkia to allow mojom::UserSession comparison.
-  // http://crbug.com/714689
-  session_controller_->UpdateUserSession(std::move(user_session));
+  if (user_session != last_sent_user_session_) {
+    last_sent_user_session_ = user_session->Clone();
+    session_controller_->UpdateUserSession(std::move(user_session));
+  }
 }
 
 void SessionControllerClient::SendUserSessionOrder() {