13. A computer-implemented method comprising: building a display tree associated with a webpage that has been received; setting at least one flag on a display tree node of the display tree associated with the webpage corresponding to an element for which a default touch behavior has been specified using a declarative style; conducting an independent hit test on the display tree associated with the webpage; and calling a manipulation thread for direct manipulation of one or more elements for which a default touch behavior has been specified.
20. The computer-implemented method of claim 13 , wherein the declarative style is associated with a property having a value that causes an associated element to be treated as a manipulation-blocking element.