Add request_id to HttpRequestInfo and pass it to the NetworkDelegate for events.

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 81160d59304fe68e4c81746c3fe10bf6418ef03e..17d7ead7d296bbbc8a05f2234ba98571df5d3397 100644
--- a/net/http/http_cache_transaction.h
+++ b/net/http/http_cache_transaction.h
@@ -141,6 +141,8 @@ class HttpCache::Transaction : public HttpTransaction {
     STATE_DOOM_ENTRY_COMPLETE,
     STATE_ADD_TO_ENTRY,
     STATE_ADD_TO_ENTRY_COMPLETE,
+    STATE_NOTIFY_BEFORE_SEND_HEADERS,
+    STATE_NOTIFY_BEFORE_SEND_HEADERS_COMPLETE,
     STATE_START_PARTIAL_CACHE_VALIDATION,
     STATE_COMPLETE_PARTIAL_CACHE_VALIDATION,
     STATE_UPDATE_CACHED_RESPONSE,
@@ -195,6 +197,8 @@ class HttpCache::Transaction : public HttpTransaction {
   int DoDoomEntryComplete(int result);
   int DoAddToEntry();
   int DoAddToEntryComplete(int result);
+  int DoNotifyBeforeSendHeaders();
+  int DoNotifyBeforeSendHeadersComplete(int result);
   int DoStartPartialCacheValidation();
   int DoCompletePartialCacheValidation(int result);
   int DoUpdateCachedResponse();