Merge 190035 "DatabaseManager::terminateDatabaseThread should ha..."

Source/modules/webdatabase/DatabaseManager.h

 /*
  * Copyright (C) 2012 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 66 matching lines @@
     // This gets a DatabaseContext for the specified ExecutionContext if
     // it already exist previously. Otherwise, it returns 0.
     DatabaseContext* existingDatabaseContextFor(ExecutionContext*);
 
     Database* openDatabaseInternal(ExecutionContext*,
         const String& name, const String& expectedVersion, const String& displayName,
         unsigned long estimatedSize, bool setVersionInNewDatabase, DatabaseError&, String& errorMessage);
 
     static void logErrorMessage(ExecutionContext*, const String& message);
 
+    // m_contextMap can have two or more entries even though we don't support
+    // Web SQL on workers because single Blink process can have multiple main
+    // contexts.
     typedef PersistentHeapHashMap<ExecutionContext*, Member<DatabaseContext> > ContextMap;
     ContextMap m_contextMap;
 #if ENABLE(ASSERT)
     int m_databaseContextRegisteredCount;
     int m_databaseContextInstanceCount;
 #endif
 };
 
 } // namespace blink
 
 #endif // DatabaseManager_h