Test 'volume' attribute

TEST(video.volume == 0.5) OK
RUN(video.volume = 1)
TEST(video.volume == 1) OK
RUN(video.volume = 0)
TEST(video.volume == 0) OK
TEST(video.volume = 1.5) THROWS(DOMException.INDEX_SIZE_ERR) OK
TEST(video.volume = -0.5) THROWS(DOMException.INDEX_SIZE_ERR) OK
RUN(video.load())
EVENT(load)
TEST(video.volume == 0) OK
RUN(video.volume = 0.5)
TEST(video.volume == 0.5) OK
TEST(video.volume = 1.5) THROWS(DOMException.INDEX_SIZE_ERR) OK
TEST(video.volume = -0.5) THROWS(DOMException.INDEX_SIZE_ERR) OK
END OF TEST