Remove case-insensitive matching of usemap attribute.

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 188 matching lines @@
                         "'navigator.webkitPersistentStorage'");
 
     case UseCounter::ConsoleMarkTimeline:
       return replacedBy("'console.markTimeline'", "'console.timeStamp'");
 
     case UseCounter::CSSStyleSheetInsertRuleOptionalArg:
       return "Calling CSSStyleSheet.insertRule() with one argument is "
              "deprecated. Please pass the index argument as well: "
              "insertRule(x, 0).";
 
-    case UseCounter::MapNameMatchingASCIICaseless:
-    case UseCounter::MapNameMatchingUnicodeLower:
-      return willBeRemoved("Case-insensitive matching for usemap attribute",
-                           M58, "5760965337415680");
-
     case UseCounter::PrefixedVideoSupportsFullscreen:
       return replacedBy("'HTMLVideoElement.webkitSupportsFullscreen'",
                         "'Document.fullscreenEnabled'");
 
     case UseCounter::PrefixedVideoDisplayingFullscreen:
       return replacedBy("'HTMLVideoElement.webkitDisplayingFullscreen'",
                         "'Document.fullscreenElement'");
 
     case UseCounter::PrefixedVideoEnterFullscreen:
       return replacedBy("'HTMLVideoElement.webkitEnterFullscreen()'",
@@ skipping 188 matching lines @@
           "-internal-media-controls-text-track-list* selectors", M59,
           "5661431349379072");
 
     // Features that aren't deprecated don't have a deprecation message.
     default:
       return String();
   }
 }
 
 }  // namespace blink