Add user name in the feedback data.

blimp/client/core/session/identity_source.cc

Index: blimp/client/core/session/identity_source.cc
diff --git a/blimp/client/core/session/identity_source.cc b/blimp/client/core/session/identity_source.cc
index 9cc74120ce7bba4cda7201b17c6a0977283abba2..2c1deffb680fa4f8b8eedde9fd375cf39175470b 100644
--- a/blimp/client/core/session/identity_source.cc
+++ b/blimp/client/core/session/identity_source.cc
@@ -66,6 +66,10 @@ void IdentitySource::Connect() {
   FetchAuthToken();
 }
 
+std::string IdentitySource::GetActiveUsername() {
+  return identity_provider_->GetActiveUsername();
+}
+
 // Add sign in state observer.
 void IdentitySource::AddObserver(IdentityProvider::Observer* observer) {
   DCHECK(identity_provider_);