Cope with a race condition in NetworkActionPredictor and NetworkActionPredictorDB initialization.

chrome/browser/autocomplete/network_action_predictor_database.cc

Index: chrome/browser/autocomplete/network_action_predictor_database.cc
diff --git a/chrome/browser/autocomplete/network_action_predictor_database.cc b/chrome/browser/autocomplete/network_action_predictor_database.cc
index 09b34fb9fa206b6e90b2160256bdddbdd15acf64..4362e57560c13a94ee6e99ced7e5aea5618f4ccf 100644
--- a/chrome/browser/autocomplete/network_action_predictor_database.cc
+++ b/chrome/browser/autocomplete/network_action_predictor_database.cc
@@ -89,7 +89,10 @@ NetworkActionPredictorDatabase::~NetworkActionPredictorDatabase() {
 
 void NetworkActionPredictorDatabase::Initialize() {
   CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
-  CHECK(!canceled_.IsSet());
+
+  if (canceled_.IsSet())
+    return;
+
   db_.set_exclusive_locking();
   if (!db_.Open(db_path_)) {
     canceled_.Set();