Web Locks API: Update spec link in mojom

Comment-only change.

TBR=dcheng@chromium.org

Change-Id: Iead1d046f07ac1f9ebce3b40d8e98bad672f3011
Reviewed-on: https://chromium-review.googlesource.com/1178305Reviewed-by: Joshua Bell <jsbell@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Joshua Bell <jsbell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583775}

third_party/blink/public/platform/modules/locks/lock_manager.mojom

@@ -46,7 +46,7 @@ struct LockInfo {
 // availablility and options. Once granted, the lock will be held until
 // explicitly released or the holding context is terminated.
 //
-// Proposal: https://github.com/inexorabletash/web-locks
+// Proposal: https://wicg.github.io/web-locks
 
 interface LockManager {
   // PREEMPT corresponds to the |steal| option in the API; if used then