(Concept patch) Simplify WTF::HashTable::add() return value for size and performance

Source/modules/webdatabase/SQLTransactionCoordinator.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 59 matching lines @@
 
 void SQLTransactionCoordinator::acquireLock(SQLTransactionBackend* transaction)
 {
     ASSERT(!m_isShuttingDown);
 
     String dbIdentifier = getDatabaseIdentifier(transaction);
 
     CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
     if (coordinationInfoIterator == m_coordinationInfoMap.end()) {
         // No pending transactions for this DB
-        coordinationInfoIterator = m_coordinationInfoMap.add(dbIdentifier, CoordinationInfo()).iterator;
+        CoordinationInfo& info = m_coordinationInfoMap.add(dbIdentifier, CoordinationInfo()).iterator->value;
+        info.pendingTransactions.append(transaction);
+        processPendingTransactions(info);
+    } else {
+        CoordinationInfo& info = coordinationInfoIterator->value;
+        info.pendingTransactions.append(transaction);
+        processPendingTransactions(info);
     }
 
-    CoordinationInfo& info = coordinationInfoIterator->value;
-    info.pendingTransactions.append(transaction);
-    processPendingTransactions(info);
 }
 
 void SQLTransactionCoordinator::releaseLock(SQLTransactionBackend* transaction)
 {
     if (m_isShuttingDown)
         return;
 
     String dbIdentifier = getDatabaseIdentifier(transaction);
 
     CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
@@ skipping 41 matching lines @@
             RefPtr<SQLTransactionBackend> transaction = info.pendingTransactions.first();
             transaction->notifyDatabaseThreadIsShuttingDown();
         }
     }
 
     // Clean up all pending transactions for all databases
     m_coordinationInfoMap.clear();
 }
 
 } // namespace WebCore