[Merge M73][NTP] Set allow='autoplay' for interactive Doodle iframe.

Allow autoplay in the interactive doodle iframe. This allows
video Doodles to play correctly, as they are implemented as an
iframe within the iframed page.

Bug: 583290
Change-Id: I491ef08dcb32dbe897b8e2041a635391d751db97
Reviewed-on: https://chromium-review.googlesource.com/c/1448523
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Reviewed-by: Ramya Nagarajan <ramyan@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#628046}(cherry picked from commit 9a624d9c1d8f4b168a31e8d2a5d69fc3ba9c71c8)
Reviewed-on: https://chromium-review.googlesource.com/c/1453543
Reviewed-by: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#190}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
diff --git a/chrome/browser/resources/local_ntp/doodles.js b/chrome/browser/resources/local_ntp/doodles.js
index 4aa99b4..b3fed19 100644
--- a/chrome/browser/resources/local_ntp/doodles.js
+++ b/chrome/browser/resources/local_ntp/doodles.js
@@ -543,6 +543,7 @@
     case doodles.LOGO_TYPE.INTERACTIVE:
       logoDoodleIframe.title = doodles.targetDoodle.metadata.altText;
       logoDoodleIframe.src = doodles.targetDoodle.metadata.fullPageUrl;
+      logoDoodleIframe.allow = 'autoplay';
       document.body.style.setProperty(
           '--logo-iframe-width',
           doodles.targetDoodle.metadata.iframeWidthPx + 'px');