Added a debug info UI for Blimp

blimp/engine/session/blimp_engine_session.cc

Index: blimp/engine/session/blimp_engine_session.cc
diff --git a/blimp/engine/session/blimp_engine_session.cc b/blimp/engine/session/blimp_engine_session.cc
index 3bf21099009ceb698e7e80c39e1545b96c552d6e..bd260cb9752c4d51efb50b831c3dbeb7f27f778b 100644
--- a/blimp/engine/session/blimp_engine_session.cc
+++ b/blimp/engine/session/blimp_engine_session.cc
@@ -23,6 +23,7 @@
 #include "blimp/engine/app/ui/blimp_window_tree_host.h"
 #include "blimp/engine/common/blimp_browser_context.h"
 #include "blimp/net/blimp_connection.h"
+#include "blimp/net/blimp_connection_details.h"
 #include "blimp/net/blimp_message_multiplexer.h"
 #include "blimp/net/blimp_message_thread_pipe.h"
 #include "blimp/net/browser_connection_handler.h"
@@ -184,6 +185,7 @@ void EngineNetworkComponents::HandleConnection(
     std::unique_ptr<BlimpConnection> connection) {
   // Observe |connection| for disconnection events.
   connection->AddConnectionErrorObserver(this);
+  connection->SetBlimpConnectionDetails(new BlimpConnectionDetails(nullptr));
   connection_handler_->HandleConnection(std::move(connection));
 }