[Android][WebSignin] Refactor continue button click listener

This CL refactors the continue button click listener to make the method
more readable.

All flows with the continue button are tested and no behavior change
in this CL.

Bug: 1124737
Change-Id: Ia99def6698786e39ec5b8c102b30ed613cb2228e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2400620
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807024}

chrome/android/java/src/org/chromium/chrome/browser/signin/account_picker/AccountPickerBottomSheetMediator.java

@@ -20,7 +20,6 @@ import org.chromium.components.signin.AccountUtils;
 import org.chromium.components.signin.AccountsChangeObserver;
 import org.chromium.components.signin.base.CoreAccountId;
 import org.chromium.components.signin.base.CoreAccountInfo;
-import org.chromium.components.signin.base.GoogleServiceAuthError;
 import org.chromium.components.signin.base.GoogleServiceAuthError.State;
 import org.chromium.ui.modelutil.PropertyModel;
 
@@ -185,33 +184,36 @@ class AccountPickerBottomSheetMediator implements AccountPickerCoordinator.Liste
      * {@link AccountPickerBottomSheetProperties#ON_CONTINUE_AS_CLICKED}.
      */
     private void onContinueAsClicked() {
-        if (mSelectedAccountName == null) {
+        @ViewState
+        int viewState = mModel.get(AccountPickerBottomSheetProperties.VIEW_STATE);
+        if (viewState == ViewState.COLLAPSED_ACCOUNT_LIST
+                || viewState == ViewState.SIGNIN_GENERAL_ERROR) {
+            signIn();
+        } else if (viewState == ViewState.NO_ACCOUNTS) {
             addAccount();
-        } else {
-            mModel.set(AccountPickerBottomSheetProperties.VIEW_STATE, ViewState.SIGNIN_IN_PROGRESS);
-            new AsyncTask<String>() {
-                @Override
-                protected String doInBackground() {
-                    return mAccountManagerFacade.getAccountGaiaId(mSelectedAccountName);
-                }
-
-                @Override
-                protected void onPostExecute(String accountGaiaId) {
-                    CoreAccountInfo coreAccountInfo = new CoreAccountInfo(
-                            new CoreAccountId(accountGaiaId), mSelectedAccountName, accountGaiaId);
-                    mAccountPickerDelegate.signIn(
-                            coreAccountInfo, AccountPickerBottomSheetMediator.this::onSignInError);
-                }
-            }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
         }
     }
 
-    private void onSignInError(GoogleServiceAuthError error) {
-        if (error.getState() == State.INVALID_GAIA_CREDENTIALS) {
-            mModel.set(AccountPickerBottomSheetProperties.VIEW_STATE, ViewState.SIGNIN_AUTH_ERROR);
-        } else {
-            mModel.set(
-                    AccountPickerBottomSheetProperties.VIEW_STATE, ViewState.SIGNIN_GENERAL_ERROR);
-        }
+    private void signIn() {
+        mModel.set(AccountPickerBottomSheetProperties.VIEW_STATE, ViewState.SIGNIN_IN_PROGRESS);
+        new AsyncTask<String>() {
+            @Override
+            protected String doInBackground() {
+                return mAccountManagerFacade.getAccountGaiaId(mSelectedAccountName);
+            }
+
+            @Override
+            protected void onPostExecute(String accountGaiaId) {
+                CoreAccountInfo coreAccountInfo = new CoreAccountInfo(
+                        new CoreAccountId(accountGaiaId), mSelectedAccountName, accountGaiaId);
+                mAccountPickerDelegate.signIn(coreAccountInfo, error -> {
+                    @ViewState
+                    int newViewState = error.getState() == State.INVALID_GAIA_CREDENTIALS
+                            ? ViewState.SIGNIN_AUTH_ERROR
+                            : ViewState.SIGNIN_GENERAL_ERROR;
+                    mModel.set(AccountPickerBottomSheetProperties.VIEW_STATE, newViewState);
+                });
+            }
+        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
 }