Bug 1457524 part 4 - Allow 16% false positives in test bloom::create_and_insert_some_stuff. r=heycam

It seems that the result of hash algorithm used in bloom filter depends
on the pointer length. On 64bit platforms, there are 135 false positives
in the first part of that test, and 8 in the second part. However, on
32bit platforms, the numbers become 157 and 16 correspondingly.

16 is still less than 20% in the second part, so all fine, but 157 is
slightly larger than 15% in the test assertion. Given it is what we are
shipping, we probably should just accept this and loosen the assertion.

MozReview-Commit-ID: 9kFXBzLFAzE

--HG--
extra : rebase_source : 41fa45dc3c59b2f44d33bdbe86b3eb2e29a31319

servo/components/selectors/bloom.rs

@@ -335,7 +335,7 @@ fn create_and_insert_some_stuff() {
 
     let false_positives = (1001_usize..2000).filter(|i| bf.might_contain(i)).count();
 
-    assert!(false_positives < 150, "{} is not < 150", false_positives); // 15%.
+    assert!(false_positives < 160, "{} is not < 160", false_positives); // 16%.
 
     for i in 0_usize..100 {
         bf.remove(&i);