Fix web audio layout test expected output

This test was reenabled in crrev.com/c/1299550, and is breaking
the Mojo Windows and Mojo Linux fyi try bots.

Bug: 841933
Change-Id: I1bfb367a3145e55ed06d966d821f9e596069d7a3
Reviewed-on: https://chromium-review.googlesource.com/c/1302325
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603174}

third_party/WebKit/LayoutTests/http/tests/webaudio/autoplay-crossorigin-expected.txt

 CONSOLE WARNING: line 13: The AudioContext was not allowed to start. It must be resumed (or created) from a user gesture event handler. https://goo.gl/7K7WLu
-CONSOLE WARNING: line 13: The Web Audio autoplay policy will be re-enabled in Chrome 70 (October 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
+CONSOLE WARNING: line 13: The Web Audio autoplay policy will be re-enabled in Chrome 71 (December 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
 CONSOLE WARNING: line 23: The AudioContext was not allowed to start. It must be resumed (or created) from a user gesture event handler. https://goo.gl/7K7WLu
 CONSOLE WARNING: line 32: The AudioContext was not allowed to start. It must be resumed (or created) from a user gesture event handler. https://goo.gl/7K7WLu
 CONSOLE WARNING: line 36: The AudioContext was not allowed to start. It must be resumed (or created) from a user gesture event handler. https://goo.gl/7K7WLu
-CONSOLE WARNING: line 36: The Web Audio autoplay policy will be re-enabled in Chrome 70 (October 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
+CONSOLE WARNING: line 36: The Web Audio autoplay policy will be re-enabled in Chrome 71 (December 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
 This is a testharness.js-based test.
 FAIL Verify that autoplaying Web Audio from a cross origin iframe is blocked by mediaPlaybackRequiresUserGesture assert_equals: stateAfterClick expected "running" but got "suspended"
 Harness: the test ran to completion.

third_party/WebKit/LayoutTests/platform/android/webaudio/dom-exceptions-expected.txt

-CONSOLE WARNING: line 39: The Web Audio autoplay policy will be re-enabled in Chrome 70 (October 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
-CONSOLE WARNING: line 43: The Web Audio autoplay policy will be re-enabled in Chrome 70 (October 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
+CONSOLE WARNING: line 39: The Web Audio autoplay policy will be re-enabled in Chrome 71 (December 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
+CONSOLE WARNING: line 43: The Web Audio autoplay policy will be re-enabled in Chrome 71 (December 2018). Please check that your website is compatible with it. https://goo.gl/7K7WLu
 CONSOLE WARNING: line 347: The provided value 'fancy' is not a valid enum value of type ChannelCountMode.
 CONSOLE WARNING: line 353: The provided value 'undefined' is not a valid enum value of type ChannelInterpretation.
 CONSOLE WARNING: line 523: The provided value '9x' is not a valid enum value of type OverSampleType.