Tentative fix of a crash in Oilpan GC after a database thread termination.

Source/modules/webdatabase/DatabaseThread.cpp

Index: Source/modules/webdatabase/DatabaseThread.cpp
diff --git a/Source/modules/webdatabase/DatabaseThread.cpp b/Source/modules/webdatabase/DatabaseThread.cpp
index d074e362041c67f51eb6083f0b07a6cdccfb2383..80574b616991586e6efc910279f87e6d487b3ea9 100644
--- a/Source/modules/webdatabase/DatabaseThread.cpp
+++ b/Source/modules/webdatabase/DatabaseThread.cpp
@@ -114,6 +114,7 @@ void DatabaseThread::cleanupDatabaseThread()
         for (HeapHashSet<Member<Database> >::iterator it = openSetCopy.begin(); it != end; ++it)
             (*it)->close();
     }
+    m_openDatabaseSet.clear();
 
     m_thread->postTask(new Task(WTF::bind(&DatabaseThread::cleanupDatabaseThreadCompleted, this)));

[haraken, 2014/10/15 08:20:18]

Just help me understand: Why do we need to post this task? Can't we just call
cleanupDatabaseThreadCompleted() here?

[tkent, 2014/10/15 08:41:22]

I don't remember the reason.  Anyway, it's unrelated to this CL.

 }
@@ -130,7 +131,9 @@ void DatabaseThread::recordDatabaseOpen(Database* database)
     ASSERT(isDatabaseThread());
     ASSERT(database);
     ASSERT(!m_openDatabaseSet.contains(database));
-    m_openDatabaseSet.add(database);
+    MutexLocker lock(m_terminationRequestedMutex);
+    if (!m_terminationRequested)
+        m_openDatabaseSet.add(database);
 }
 
 void DatabaseThread::recordDatabaseClosed(Database* database)