mash: Have chrome set itself as a controller interface for changing volume

ash/mus/manifest.json

Index: ash/mus/manifest.json
diff --git a/ash/mus/manifest.json b/ash/mus/manifest.json
index ab525538d6842810e17ef4134b7a7501c4264855..c1c74dc8d436f3231a15877ebaf2089a403e4fdb 100644
--- a/ash/mus/manifest.json
+++ b/ash/mus/manifest.json
@@ -4,7 +4,10 @@
   "interface_provider_specs": {
     "service_manager:connector": {
       "provides": {
+        // See also chrome_content_browser_manifest_overlay.json for classic ash

[msw, 2016/12/06 19:43:57]

Hmm, I'm not sure how this comment is helpful? What are you hoping to convey?

[James Cook, 2016/12/06 20:11:53]

I'm trying to convey the fact that when you add an interface in ash you need to
add it to two files.

Sadly, we don't have google3's "if you change this" annotation
https://drive.google.com/file/d/0B-KFDiTrQe9lenFxcXVFbURDeDA/view

[msw, 2016/12/06 20:13:29]

Maybe explicitly say "Modifications here should correspond with changes to ..."
or similar.

[James Cook, 2016/12/06 20:19:15]

Yeah, that's better. Done.

+        // when these interfaces are provided by content_browser.
         "ash": [
+          "ash::mojom::AcceleratorController",
           "ash::mojom::CastConfig",
           "ash::mojom::LocaleNotificationController",
           "ash::mojom::ShelfController",