Remove dependency of SSLPlatformKeyTaskRunner on single-threaded SequencedWorkerPool.

net/ssl/threaded_ssl_private_key.cc

 // 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.
 
 #include "net/ssl/threaded_ssl_private_key.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
-#include "base/task_runner.h"
+#include "base/single_thread_task_runner.h"
 #include "base/task_runner_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 
 namespace net {
 
 namespace {
 
 void DoCallback(const base::WeakPtr<ThreadedSSLPrivateKey>& key,
                 const ThreadedSSLPrivateKey::SignCallback& callback,
                 std::vector<uint8_t>* signature,
@@ skipping 20 matching lines @@
 
  private:
   friend class base::RefCountedThreadSafe<Core>;
   ~Core() {}
 
   std::unique_ptr<ThreadedSSLPrivateKey::Delegate> delegate_;
 };
 
 ThreadedSSLPrivateKey::ThreadedSSLPrivateKey(
     std::unique_ptr<ThreadedSSLPrivateKey::Delegate> delegate,
-    scoped_refptr<base::TaskRunner> task_runner)
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
     : core_(new Core(std::move(delegate))),
       task_runner_(std::move(task_runner)),
       weak_factory_(this) {}
 
 SSLPrivateKey::Type ThreadedSSLPrivateKey::GetType() {
   return core_->delegate()->GetType();
 }
 
 std::vector<SSLPrivateKey::Hash> ThreadedSSLPrivateKey::GetDigestPreferences() {
   return core_->delegate()->GetDigestPreferences();
@@ skipping 12 matching lines @@
       task_runner_.get(), FROM_HERE,
       base::Bind(&ThreadedSSLPrivateKey::Core::SignDigest, core_, hash,
                  input.as_string(), base::Unretained(signature)),
       base::Bind(&DoCallback, weak_factory_.GetWeakPtr(), callback,
                  base::Owned(signature)));
 }
 
 ThreadedSSLPrivateKey::~ThreadedSSLPrivateKey() {}
 
 }  // namespace net