Replace RemoveWithoutPathExpansion(.*, nullptr) with Value::RemoveKey()

DictionaryValue::RemoveWithoutPathExpansion() is deprecated. For the
case where nullptr is passed for the output argument, Value::RemoveKey()
is a trivial replacement.

Mostly done with the following command line, plus a bit of finesse:
% git grep -l RemoveWithoutPathExpansion | \
  xargs sed -E -i 's/RemoveWithoutPathExpansion\((.*), nullptr/RemoveKey\(\1/g'

Bug: 646113

This CL was uploaded by git cl split.

R=khorimoto@chromium.org

Change-Id: I9471132239f2ff79dfb6c60ddd31389fbba2aef4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2298840
Auto-Submit: Anand K Mistry <amistry@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#788466}

chrome/browser/chromeos/login/easy_unlock/easy_unlock_service.cc

@@ -152,7 +152,7 @@ void EasyUnlockService::ResetLocalStateForUser(const AccountId& account_id) {
     return;
 
   DictionaryPrefUpdate update(local_state, prefs::kEasyUnlockHardlockState);
-  update->RemoveWithoutPathExpansion(account_id.GetUserEmail(), NULL);
+  update->RemoveKey(account_id.GetUserEmail());
 
   EasyUnlockTpmKeyManager::ResetLocalStateForUser(account_id);
 }

chrome/browser/chromeos/login/easy_unlock/easy_unlock_service_regular.cc

@@ -265,7 +265,7 @@ void EasyUnlockServiceRegular::SetStoredRemoteDevices(
   DictionaryPrefUpdate pairing_update(profile()->GetPrefs(),
                                       prefs::kEasyUnlockPairing);
   if (devices.empty())
-    pairing_update->RemoveWithoutPathExpansion(kKeyDevices, NULL);
+    pairing_update->RemoveKey(kKeyDevices);
   else
     pairing_update->SetKey(kKeyDevices, devices.Clone());
 

chrome/browser/chromeos/login/easy_unlock/easy_unlock_tpm_key_manager.cc

@@ -199,7 +199,7 @@ void EasyUnlockTpmKeyManager::ResetLocalStateForUser(
     return;
 
   DictionaryPrefUpdate update(local_state, prefs::kEasyUnlockLocalStateTpmKeys);
-  update->RemoveWithoutPathExpansion(account_id.GetUserEmail(), NULL);
+  update->RemoveKey(account_id.GetUserEmail());
 }
 
 EasyUnlockTpmKeyManager::EasyUnlockTpmKeyManager(