Fix baseline of fast/beacon/beacon-basic.html on Android

The test has an Android-specific baseline, which was missed out in
crrev.com/c/1278210, causing bot failures.

This patch fixes it.

NoTry: True
Tbr: tkent@chromium.org
Bug: 887148, 896310
Change-Id: I1448139afce05792e72f659dd528bf6b90e3d993
Reviewed-on: https://chromium-review.googlesource.com/c/1297406Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602121}

third_party/WebKit/LayoutTests/platform/android/fast/beacon/beacon-basic-expected.txt

@@ -2,7 +2,6 @@ Exercising the Beacon API
 
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
-
 PASS Object.getPrototypeOf(navigator).hasOwnProperty('sendBeacon') is true
 PASS typeof navigator.sendBeacon is "function"
 PASS navigator.sendBeacon() threw exception TypeError: Failed to execute 'sendBeacon' on 'Navigator': 1 argument required, but only 0 present..