[Autoplay] Sound setting should be top level scope

The sound setting is only applied at a WebContents
level so we should make sure it is registered with
TOP_LEVEL_ORIGIN_ONLY_SCOPE.

BUG=865548

Change-Id: Ia0e02f2201665b14a59e8c38b8dcfcde8e99ed67
Reviewed-on: https://chromium-review.googlesource.com/1169522
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582234}

components/content_settings/core/browser/content_settings_registry.cc

@@ -296,7 +296,7 @@ void ContentSettingsRegistry::Init() {
   Register(CONTENT_SETTINGS_TYPE_SOUND, "sound", CONTENT_SETTING_ALLOW,
            WebsiteSettingsInfo::UNSYNCABLE, WhitelistedSchemes(),
            ValidSettings(CONTENT_SETTING_ALLOW, CONTENT_SETTING_BLOCK),
-           WebsiteSettingsInfo::REQUESTING_ORIGIN_ONLY_SCOPE,
+           WebsiteSettingsInfo::TOP_LEVEL_ORIGIN_ONLY_SCOPE,
            WebsiteSettingsRegistry::DESKTOP |
                WebsiteSettingsRegistry::PLATFORM_ANDROID,
            ContentSettingsInfo::INHERIT_IN_INCOGNITO,