[mojo][SM] Remove AudioContextManager from content browser manifest

This change removes blink.mojom.AudioContextManager from the
"navigation:frame" capability of content_browser service name since
DocumentInterfaceBroker is used to acquire this interface as of
https://crrev.com/c/1497378

Bug: 936482
Change-Id: I9f8667121241dbf5c6e1dcd27eb28746f3c667fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1529583Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Oksana Zhuravlova <oksamyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642736}

content/public/app/content_browser_manifest.cc

@@ -200,7 +200,6 @@ const service_manager::Manifest& GetContentBrowserManifest() {
                   "autofill.mojom.AutofillDriver",
                   "autofill.mojom.PasswordManagerDriver",
                   "blink.mojom.AnchorElementMetricsHost",
-                  "blink.mojom.AudioContextManager",
                   "blink.mojom.Authenticator",
                   "blink.mojom.BackgroundFetchService",
                   "blink.mojom.CacheStorage",