Remove support for the keygen tag

content/renderer/renderer_blink_platform_impl.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_RENDERER_RENDERER_BLINK_PLATFORM_IMPL_H_
 #define CONTENT_RENDERER_RENDERER_BLINK_PLATFORM_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 98 matching lines @@
       const blink::WebString& vfs_file_name) override;
   long long databaseGetFileSize(const blink::WebString& vfs_file_name) override;
   long long databaseGetSpaceAvailableForOrigin(
       const blink::WebSecurityOrigin& origin) override;
   bool databaseSetFileSize(const blink::WebString& vfs_file_name,
                            long long size) override;
   blink::WebString databaseCreateOriginIdentifier(
       const blink::WebSecurityOrigin& origin) override;
   cc::FrameSinkId generateFrameSinkId() override;
 
-  blink::WebString signedPublicKeyAndChallengeString(
-      unsigned key_size_index,
-      const blink::WebString& challenge,
-      const blink::WebURL& url,
-      const blink::WebURL& top_origin) override;
   void getPluginList(bool refresh,
                      const blink::WebSecurityOrigin& mainFrameOrigin,
                      blink::WebPluginListBuilder* builder) override;
   blink::WebPublicSuffixList* publicSuffixList() override;
   blink::WebScrollbarBehavior* scrollbarBehavior() override;
   blink::WebIDBFactory* idbFactory() override;
   blink::WebServiceWorkerCacheStorage* cacheStorage(
       const blink::WebSecurityOrigin& security_origin) override;
   blink::WebFileSystem* fileSystem() override;
   blink::WebString fileSystemCreateOriginIdentifier(
@@ skipping 168 matching lines @@
   std::unique_ptr<BlinkInterfaceProviderImpl> blink_interface_provider_;
 
   mojom::URLLoaderFactoryAssociatedPtr url_loader_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererBlinkPlatformImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDERER_BLINK_PLATFORM_IMPL_H_