Refactor the Heap into ThreadHeap to prepare for per thread heaps

third_party/WebKit/Source/modules/webdatabase/SQLTransaction.cpp

 /*
  * Copyright (C) 2007, 2008, 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:
  *
  * 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
@@ skipping 47 matching lines @@
 SQLTransaction::SQLTransaction(Database* db, SQLTransactionCallback* callback,
     VoidCallback* successCallback, SQLTransactionErrorCallback* errorCallback,
     bool readOnly)
     : m_database(db)
     , m_callback(callback)
     , m_successCallback(successCallback)
     , m_errorCallback(errorCallback)
     , m_executeSqlAllowed(false)
     , m_readOnly(readOnly)
 {
+    ASSERT(isMainThread());
     ASSERT(m_database);
     m_asyncOperationId = InspectorInstrumentation::traceAsyncOperationStarting(db->executionContext(), "SQLTransaction");
 }
 
 SQLTransaction::~SQLTransaction()
 {
 }
 
 DEFINE_TRACE(SQLTransaction)
 {
@@ skipping 255 matching lines @@
     m_successCallback.clear();
     m_errorCallback.clear();
 }
 
 SQLTransactionErrorCallback* SQLTransaction::releaseErrorCallback()
 {
     return m_errorCallback.release();
 }
 
 } // namespace blink