Attrib

This is more of a style cleanup in the sub directory.  The changes I made in some other sub directories have more meaningful stuff, but I did clean things up as I scanned through various files.
Here and throughout this review, the removal of the inline js-test-post.js script and the use of finishTest() will cause the script node which loads js-test-post.js to be created asynchronously. I thought I remembered seeing a situation while investigating crbug.com/407976 where it looked like js-test-post.js wasn't loaded successfully. I'm not sure it is a good idea to make the change to call finishTest() in all of these tests instead of just leaving them with "var successfullyParsed = true;" as the last statement, and loading js-test-post.js directly. Note that these vertex attrib tests have not been flaky. I think that this change could make them start to be flaky.