Use Length for baselineShiftValue in SVGLayoutStyle

LayoutTests/svg/css/script-tests/scientific-numbers.js

 description("Test scientific numbers on <length> values for SVG presentation attributes.")
 if (window.testRunner)
     testRunner.dumpAsText();
 createSVGTestCase();
 
 var text = createSVGElement("text");
 text.setAttribute("id", "text");
 text.setAttribute("x", "100px");
 text.setAttribute("y", "100px");
 rootSVGElement.appendChild(text);
 
 function test(valueString, expectedValue) {
-        // Reset baseline-shift to baseline.
-        text.setAttribute("baseline-shift", "baseline");
-        shouldBeEqualToString("getComputedStyle(text).baselineShift", "baseline");
+    // Reset baseline-shift to baseline.
+    text.style.baselineShift = "baseline";
+    shouldBeEqualToString("text.style.baselineShift", "baseline");
 
-        // Run test
-        text.setAttribute("baseline-shift", valueString);
-        shouldBeEqualToString("getComputedStyle(text).baselineShift", expectedValue);
+    // Run test
+    text.style.baselineShift = valueString;
+    shouldBeEqualToString("text.style.baselineShift", expectedValue);
 }
 
 debug("");
 debug("Test positive exponent values with 'e'");
 test(".5e2", "50px");
 test("5e1", "50px");
 test("0.5e2", "50px");
 test("+.5e2", "50px");
 test("+5e1", "50px");
 test("+0.5e2", "50px");
@@ skipping 58 matching lines @@
 debug("");
 debug("Invalid values");
 test("50e0.0", "baseline");
 test("50 e0", "baseline");
 test("50e 0", "baseline");
 test("50.e0", "baseline");
 
 var successfullyParsed = true;
 
 completeTest();