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

components/login/screens/screen_context.cc

Index: components/login/screens/screen_context.cc
diff --git a/components/login/screens/screen_context.cc b/components/login/screens/screen_context.cc
index 5e170b682d8f5d7cb067599ad90e56ab76891b6c..3473d9c3fcab7fc5f1445f9540f9d2a83f64a612 100644
--- a/components/login/screens/screen_context.cc
+++ b/components/login/screens/screen_context.cc
@@ -29,6 +29,7 @@ ScreenContext::ScreenContext() {
 }
 
 ScreenContext::~ScreenContext() {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 }
 
 bool ScreenContext::SetBoolean(const KeyType& key, bool value) {
@@ -131,17 +132,17 @@ void ScreenContext::CopyFrom(ScreenContext& context) {
 }
 
 bool ScreenContext::HasKey(const KeyType& key) const {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   return storage_.HasKey(key);
 }
 
 bool ScreenContext::HasChanges() const {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   return !changes_.empty();
 }
 
 void ScreenContext::GetChangesAndReset(base::DictionaryValue* diff) {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   DCHECK(diff);
   changes_.Swap(diff);
   changes_.Clear();
@@ -149,7 +150,7 @@ void ScreenContext::GetChangesAndReset(base::DictionaryValue* diff) {
 
 void ScreenContext::ApplyChanges(const base::DictionaryValue& diff,
                                  std::vector<std::string>* keys) {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   DCHECK(!HasChanges());
   if (keys) {
     keys->clear();
@@ -165,7 +166,7 @@ void ScreenContext::ApplyChanges(const base::DictionaryValue& diff,
 }
 
 bool ScreenContext::Set(const KeyType& key, base::Value* value) {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   DCHECK(value);
   std::unique_ptr<base::Value> new_value(value);