Add milestone to deprecation message for EME on insecure contexts

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/Deprecation.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/frame/FrameConsole.h"
 #include "core/frame/FrameHost.h"
@@ skipping 297 matching lines @@
              "See https://goo.gl/rStTGz for more details.";
 
     case UseCounter::GetUserMediaInsecureOrigin:
     case UseCounter::GetUserMediaInsecureOriginIframe:
       return "getUserMedia() no longer works on insecure origins. To use this "
              "feature, you should consider switching your application to a "
              "secure origin, such as HTTPS. See https://goo.gl/rStTGz for more "
              "details.";
 
     case UseCounter::EncryptedMediaInsecureOrigin:
-      return "requestMediaKeySystemAccess() is deprecated on insecure origins "
-             "in the specification. Support will be removed in the future. You "
-             "should consider switching your application to a secure origin, "
-             "such as HTTPS. See https://goo.gl/rStTGz for more details.";
+      return String::format(
+          "Using requestMediaKeySystemAccess() on insecure origins is "
+          "deprecated and will be removed in %s. You should consider "
+          "switching your application to a secure origin, such as HTTPS. See "
+          "https://goo.gl/rStTGz for more details.",
+          milestoneString(M58));
 
     case UseCounter::MediaSourceAbortRemove:
       return "Using SourceBuffer.abort() to abort remove()'s asynchronous "
              "range removal is deprecated due to specification change. Support "
              "will be removed in the future. You should instead await "
              "'updateend'. abort() is intended to only abort an asynchronous "
              "media append or reset parser state. See "
              "https://www.chromestatus.com/features/6107495151960064 for more "
              "details.";
     case UseCounter::MediaSourceDurationTruncatingBuffered:
@@ skipping 81 matching lines @@
           "redirected response. This will result in an error in %s.",
           milestoneString(M59));
 
     // Features that aren't deprecated don't have a deprecation message.
     default:
       return String();
   }
 }
 
 }  // namespace blink