Rename requireUserMediation to preventSilentAccess in the CM API.

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/LocalFrame.h"
@@ skipping 407 matching lines @@
     case UseCounter::kCredentialManagerAdditionalData:
     case UseCounter::kCredentialManagerCustomFetch:
       return String::Format(
           "Passing 'PasswordCredential' objects into 'fetch(..., { "
           "credentials: ... })' is deprecated, and will be removed in %s. See "
           "https://www.chromestatus.com/features/5689327799500800 for more "
           "details and https://www.chromium.org/developers/"
           "recent-changes-credential-management-api for migration suggestions.",
           milestoneString(M62));
 
+    case UseCounter::kCredentialManagerRequireUserMediation:
+      return String::Format(
+          "'requireUserMediation' was renamed to 'preventSilentAccess'. The "
+          "method will be removed in %s.",
+          milestoneString(M62));

[Mike West, 2017/05/23 18:54:32]

Nit: I'd suggest something like:

```
return replacedWillBeRemoved(
    "The CredentialsContainer.requireUserMediation method",
    "the CredentialsContainer.preventSilentAccess method",
    M62,
    "4781762488041472");
```

[vasilii, 2017/05/24 10:02:13]

Done.

+
     // Features that aren't deprecated don't have a deprecation message.
     default:
       return String();
   }
 }
 
 }  // namespace blink