Replace deprecated base::NonThreadSafe in components/login in favor of SequenceChecker.

components/login/screens/screen_context.h

 // Copyright (c) 2013 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 COMPONENTS_LOGIN_SCREENS_SCREEN_CONTEXT_H_
 #define COMPONENTS_LOGIN_SCREENS_SCREEN_CONTEXT_H_
 
 #include <string>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/sequence_checker.h"
 #include "base/strings/string16.h"
-#include "base/threading/non_thread_safe.h"
 #include "base/values.h"
 #include "components/login/base_screen_handler_utils.h"
 #include "components/login/login_export.h"
 
 namespace login {
 
 // ScreenContext is a key-value storage for values that are shared
 // between C++ and JS sides. Objects of this class should be used in
 // the following way:
 //
 // context.SetString("user", "john");
 // context.SetInteger("image-index", 0);
 // context.SetDouble("zoom", 1.25);
 // context.GetChangesAndReset(&dictionary);
 // CallJS("onContextChanged", dictionary);
 //
 // ScreenContext memorizes changed key-value pairs and returns them
 // via GetChangesAndReset() method. After call to this method an
 // internal buffer of changes will be cleared.
-class LOGIN_EXPORT ScreenContext : public base::NonThreadSafe {
+class LOGIN_EXPORT ScreenContext {
  public:
   typedef std::string KeyType;
   typedef base::Value ValueType;
 
   ScreenContext();
   ~ScreenContext();
 
   bool SetBoolean(const KeyType& key, bool value);
   bool SetInteger(const KeyType& key, int value);
   bool SetDouble(const KeyType& key, double value);
@@ skipping 42 matching lines @@
                     std::vector<std::string>* keys);
 
   // Returns underlying dictionary containing all the stored data.
   const base::DictionaryValue& storage() const { return storage_; }
 
  private:
   bool Set(const KeyType& key, base::Value* value);
 
   template <typename T>
   T Get(const KeyType& key) const {
-    DCHECK(CalledOnValidThread());
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     const base::Value* value;
     bool has_key = storage_.Get(key, &value);
     DCHECK(has_key);
     T result;
     if (!ParseValue(value, &result)) {
       NOTREACHED();
       return T();
     }
     return result;
   }
 
   template <typename T>
   T Get(const KeyType& key, const T& default_value) const {
-    DCHECK(CalledOnValidThread());
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     if (!HasKey(key))
       return default_value;
     return Get<T>(key);
   }
 
   // Contains current state of <key, value> map.
   base::DictionaryValue storage_;
 
   // Contains all pending changes.
   base::DictionaryValue changes_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(ScreenContext);
 };
 
 }  // namespace login
 
 #endif  // COMPONENTS_LOGIN_SCREENS_SCREEN_CONTEXT_H_