Stop using CertStore which is not compatible with PlzNavigate.

ios/web/net/cert_store_impl.h

Index: ios/web/net/cert_store_impl.h
diff --git a/ios/web/net/cert_store_impl.h b/ios/web/net/cert_store_impl.h
deleted file mode 100644
index 04cde7d80fe78d89b3349f9301afaed5413bc9f1..0000000000000000000000000000000000000000
--- a/ios/web/net/cert_store_impl.h
+++ /dev/null
@@ -1,62 +0,0 @@
-// Copyright 2015 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 IOS_WEB_NET_CERT_STORE_IMPL_H_
-#define IOS_WEB_NET_CERT_STORE_IMPL_H_
-
-#include "base/macros.h"
-#include "base/memory/singleton.h"
-#include "ios/web/net/request_tracker_data_memoizing_store.h"
-#include "ios/web/public/cert_store.h"
-#include "net/cert/x509_certificate.h"
-
-namespace web {
-
-class CertStoreImpl : public CertStore {
- public:
-  // Returns the singleton instance of the CertStore.
-  static CertStoreImpl* GetInstance();
-
-  // CertStore implementation:
-  int StoreCert(net::X509Certificate* cert, int group_id) override;
-  bool RetrieveCert(int cert_id,
-                    scoped_refptr<net::X509Certificate>* cert) override;
-  void RemoveCertsForGroup(int group_id) override;
-
- protected:
-  CertStoreImpl();
-  ~CertStoreImpl() override;
-
- private:
-  friend struct base::DefaultSingletonTraits<CertStoreImpl>;
-
-  // Utility structure that allows memoization to be based on the
-  // hash of |cert|'s certificate chain, to avoid needing to compare
-  // every certificate individually. This is purely an optimization.
-  class HashAndCert : public base::RefCountedThreadSafe<HashAndCert> {
-   public:
-    HashAndCert();
-
-    // Comparator for RendererDataMemoizingStore.
-    struct LessThan {
-      bool operator()(const scoped_refptr<HashAndCert>& lhs,
-                      const scoped_refptr<HashAndCert>& rhs) const;
-    };
-
-    net::SHA256HashValue chain_hash;
-    scoped_refptr<net::X509Certificate> cert;
-
-   private:
-    friend class base::RefCountedThreadSafe<HashAndCert>;
-
-    ~HashAndCert();
-  };
-  RequestTrackerDataMemoizingStore<HashAndCert> store_;
-
-  DISALLOW_COPY_AND_ASSIGN(CertStoreImpl);
-};
-
-}  // namespace web
-
-#endif  // IOS_WEB_NET_CERT_STORE_IMPL_H_