HasAutoChartDepth Property
From Microsoft Office Web Components Object Model
HasAutoChartDepth Property
False if the depth of the specified chart has been modified. Set this property to True to restore the specified chart to its default depth. Read-write Boolean.
expression.HasAutoChartDepth
expression Required. An expression that returns a ChChart object.
Example
This example resets the first chart in Chartspace1 to it's default depth.
Chartspace1.Charts(0).HasAutoChartDepth = True