removed unnecessary xml trace

Change-Id: Ifc294e8c76e69bf7595dcad144975e00b27063d8
prevent null pointer error

Change-Id: I23fe61d3e25b21d9d41a03384b7b466763ecbf3e
added JavaScript API function loadFile()

Change-Id: I65c23cfd8c5f9f2dce7583373addce2c25f6804a