[bindings] Remove SQLTransaction's usage of custom binding.

Source/modules/webdatabase/SQLTransaction.idl

Index: Source/modules/webdatabase/SQLTransaction.idl
diff --git a/Source/modules/webdatabase/SQLTransaction.idl b/Source/modules/webdatabase/SQLTransaction.idl
index 2213ed76931e0a8c8e406d4551cddf30bf541490..96319a1f7e5ad298afdd3b11cf1c0126fba9fc06 100644
--- a/Source/modules/webdatabase/SQLTransaction.idl
+++ b/Source/modules/webdatabase/SQLTransaction.idl
@@ -26,13 +26,15 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+typedef sequence<any> ObjectArray;
+
 [
     GarbageCollected,
     NoInterfaceObject,
 ] interface SQLTransaction {
-    [Custom] void executeSql(DOMString sqlStatement,
-                             object[] arguments,
-                             optional SQLStatementCallback callback,
-                             optional SQLStatementErrorCallback errorCallback);
+    [RaisesException] void executeSql(DOMString sqlStatement,
+                      optional ObjectArray? arguments,

[vivekg, 2015/02/24 09:58:15]

How can we specify ObjectArray can be a null. Right now there is no way in which
this can be specified either:

optional ObjectArray? arguments = null 

or 

optional object[]? arguments = null

Which is the correct way to support this? Or is this a valid construct at all? 

+                      optional SQLStatementCallback callback,
+                      optional SQLStatementErrorCallback errorCallback);
 
 };