[HttpCache::Transaction] Ensure each state only sets the next state once

net/http/http_cache_transaction.h

Index: net/http/http_cache_transaction.h
diff --git a/net/http/http_cache_transaction.h b/net/http/http_cache_transaction.h
index 0998695962e19cf1b36f0221355487a21189af77..46126c78de08833eff2f0538b092132f5208831a 100644
--- a/net/http/http_cache_transaction.h
+++ b/net/http/http_cache_transaction.h
@@ -434,6 +434,10 @@ class HttpCache::Transaction : public HttpTransaction {
   // Called to signal completion of asynchronous IO.
   void OnIOComplete(int result);
 
+  // When in a DoLoop, use this to set the next state as it verifies that the
+  // state isn't set twice.
+  void SetNextStateFromDoLoop(State state);

[Randy Smith (Not in Mondays), 2017/03/22 15:42:12]

Mild preference for something like "TransitionTo", just because it's shorter and
I think it implies we're in the DoLoop() context, but I totally get if you don't
think that's explicit enough.

[jkarlin, 2017/03/22 17:12:00]

Done. Renamed to TransitionToState.

+
   State next_state_;
   const HttpRequestInfo* request_;
   RequestPriority priority_;
@@ -508,6 +512,9 @@ class HttpCache::Transaction : public HttpTransaction {
   BeforeNetworkStartCallback before_network_start_callback_;
   BeforeHeadersSentCallback before_headers_sent_callback_;
 
+  // True if the Transaction is currently processing the DoLoop.
+  bool in_do_loop_;
+
   base::WeakPtrFactory<Transaction> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Transaction);