Warn about Web Audio without user gesture on Android no longer allowed on cross origin iframes.

third_party/WebKit/Source/core/frame/Deprecation.cpp

Index: third_party/WebKit/Source/core/frame/Deprecation.cpp
diff --git a/third_party/WebKit/Source/core/frame/Deprecation.cpp b/third_party/WebKit/Source/core/frame/Deprecation.cpp
index 1ff6fca897d3af5ad55639f5f3f5d71753afe168..9a9fe1e0cc2c6918c05a0ffec173f6c6c92e1e5c 100644
--- a/third_party/WebKit/Source/core/frame/Deprecation.cpp
+++ b/third_party/WebKit/Source/core/frame/Deprecation.cpp
@@ -376,6 +376,9 @@ String Deprecation::deprecationMessage(UseCounter::Feature feature)
     case UseCounter::NavigatorPointerEnabled:
         return "Navigator.pointerEnabled is a non-standard API added for experiments only. It will be removed in near future.";
 
+    case UseCounter::WebAudioAutoplayCrossOriginIframe:
+        return willBeRemoved("Web Audio autoplay (without user gesture) from cross-origin iframes", 55, "6406908126691328");
+
     // Features that aren't deprecated don't have a deprecation message.
     default:
         return String();