Smart Lock: Do not start multiple auth attempts.

EasyUnlockService previously re-instantiated an EasyUnlockAuthAttempt
every time the user profile picture was tapped or clicked. This was
unnecessary, and caused situations where the account's cryptohome
could not be decrypted.

Bug: 896045
Change-Id: I959ed3209caeb8d83519c8300d863a6288984740
Reviewed-on: https://chromium-review.googlesource.com/c/1285118
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600190}

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

@@ -363,7 +363,7 @@ bool EasyUnlockService::UpdateScreenlockState(ScreenlockState state) {
   if (state == ScreenlockState::AUTHENTICATED) {
     if (power_monitor_)
       power_monitor_->RecordStartUpTime();
-  } else if (auth_attempt_.get()) {
+  } else if (auth_attempt_) {
     // Clean up existing auth attempt if we can no longer authenticate the
     // remote device.
     auth_attempt_.reset();
@@ -381,8 +381,13 @@ void EasyUnlockService::AttemptAuth(const AccountId& account_id) {
   const EasyUnlockAuthAttempt::Type auth_attempt_type =
       GetType() == TYPE_REGULAR ? EasyUnlockAuthAttempt::TYPE_UNLOCK
                                 : EasyUnlockAuthAttempt::TYPE_SIGNIN;
+  if (auth_attempt_) {
+    PA_LOG(INFO) << "Already attempting auth, skipping this request.";
+    return;
+  }
+
   if (!GetAccountId().is_valid()) {
-    LOG(ERROR) << "Empty user account. Refresh token might go bad.";
+    PA_LOG(ERROR) << "Empty user account. Auth attempt failed.";
     return;
   }
 
@@ -403,7 +408,7 @@ void EasyUnlockService::AttemptAuth(const AccountId& account_id) {
 }
 
 void EasyUnlockService::FinalizeUnlock(bool success) {
-  if (!auth_attempt_.get())
+  if (!auth_attempt_)
     return;
 
   this->OnWillFinalizeUnlock(success);
@@ -421,8 +426,9 @@ void EasyUnlockService::FinalizeUnlock(bool success) {
 }
 
 void EasyUnlockService::FinalizeSignin(const std::string& key) {
-  if (!auth_attempt_.get())
+  if (!auth_attempt_)
     return;
+
   std::string wrapped_secret = GetWrappedSecret();
   if (!wrapped_secret.empty())
     auth_attempt_->FinalizeSignin(GetAccountId(), wrapped_secret, key);