Use new web-page-replay mirror.

Old one was broken by a "git push --force".
The new mirror's path makes it clear that it is a github mirror.

BUG=470159

Review URL: https://codereview.chromium.org/1046473002

Cr-Commit-Position: refs/heads/master@{#322693}

DEPS

@@ -266,7 +266,7 @@ deps = {
    Var('chromium_git') + '/chromium/tools/deps2git.git' + '@' + 'f04828eb0b5acd3e7ad983c024870f17f17b06d9',
 
   'src/third_party/webpagereplay':
-   Var('chromium_git') + '/external/web-page-replay.git' + '@' + '532b413ff95e8595d5028e0dae75dcf3ba712d2e',
+   Var('chromium_git') + '/external/github.com/chromium/web-page-replay.git' + '@' + '5e6780f1f762f635c8f45865308db520c29ac3d8',
 
   'src/third_party/pywebsocket/src':
     Var('chromium_git') + '/external/pywebsocket/src.git' + '@' + 'cb349e87ddb30ff8d1fa1a89be39cec901f4a29c',