Whitespace.

For manual commit.

BUG=668624
TBR=kjellander@webrtc.org
NOTRY=True
NOPRESUBMIT=True

Review URL: https://codereview.webrtc.org/2547553002 .

Cr-Commit-Position: refs/heads/master@{#15361}

tools/whitespace.txt

@@ -4,4 +4,3 @@ Try to write something funny. And please don't add trailing whitespace.
 Whitespaces are cool, except when they're trailing. They they're kind of
 80s.
 Here's a funny story: What do you call a root beer in a square glass? Beer!
-not-a-whitespace