Bug 1301671 - Roll back non-nullable check for getAttachedShaders in tests.

MozReview-Commit-ID: 7rijDHSi2JW

dom/canvas/test/webgl-conf/checkout/js/tests/gl-object-get-calls.js

@@ -315,8 +315,8 @@ var shaders = gl.getAttachedShaders(standardProgram);
 shouldBe('shaders.length', '2');
 shouldBeTrue('shaders[0] == standardVert && shaders[1] == standardFrag || shaders[1] == standardVert && shaders[0] == standardFrag');
 wtu.glErrorShouldBe(gl, gl.NO_ERROR);
-shouldThrow('gl.getAttachedShaders(null)');
-wtu.glErrorShouldBe(gl, gl.NO_ERROR);
+gl.getAttachedShaders(null);
+wtu.glErrorShouldBe(gl, gl.INVALID_VALUE);
 shouldThrow('gl.getAttachedShaders(standardVert)');
 wtu.glErrorShouldBe(gl, gl.NO_ERROR);