[oilpan]: Add SafePointAwareMutexLocker to allow GC when waiting for lock.

Source/modules/webdatabase/sqlite/SQLiteStatement.cpp

Index: Source/modules/webdatabase/sqlite/SQLiteStatement.cpp
diff --git a/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp b/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp
index c7691d030ad16aebca521821daa242876507aac1..3ae9f8156db5bb107e2e591d172621c8aacf7e95 100644
--- a/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp
+++ b/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp
@@ -59,12 +59,13 @@ int SQLiteStatement::prepare()
 {
     ASSERT(!m_isPrepared);
 
+    CString query = m_query.stripWhiteSpace().utf8();
+
+    ThreadState::SafePointScope scope(ThreadState::HeapPointersOnStack);
     MutexLocker databaseLock(m_database.databaseMutex());
     if (m_database.isInterrupted())
         return SQLITE_INTERRUPT;
 
-    CString query = m_query.stripWhiteSpace().utf8();
-
     WTF_LOG(SQLDatabase, "SQL - prepare - %s", query.data());
 
     // Pass the length of the string including the null character to sqlite3_prepare_v2;
@@ -87,6 +88,7 @@ int SQLiteStatement::prepare()
 
 int SQLiteStatement::step()
 {
+    ThreadState::SafePointScope scope(ThreadState::HeapPointersOnStack);
     MutexLocker databaseLock(m_database.databaseMutex());
     if (m_database.isInterrupted())
         return SQLITE_INTERRUPT;