[Android][Signin] Add utility methods to CoreAccountInfo

Adds a getAndroidAccount, getId, getEmail, getGaiaId static helpers to
CoreAccountInfo. These helpers all do the same task - they return
Account/CoreAccountId/Email/GaiaId from the argument if it's not null,
and return null otherwise. IdentityManager.getPrimaryAccountId will be
replaced by this in subsequent CLs.

Bug: 1051000
Change-Id: Id0cc2bb5049f5464cbfc06a4866c7a9bf2074724
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2061813
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Auto-Submit: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Alice Wang <aliceywang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743082}

components/signin/public/android/java/src/org/chromium/components/signin/base/CoreAccountInfo.java

@@ -4,9 +4,13 @@
 
 package org.chromium.components.signin.base;
 
+import android.accounts.Account;
+
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 import org.chromium.base.annotations.CalledByNative;
+import org.chromium.components.signin.AccountManagerFacade;
 
 /**
  * Structure storing the core information about a Google account that is always known. The {@link
@@ -80,4 +84,42 @@ public class CoreAccountInfo {
         return mId.equals(other.mId) && mEmail.equals(other.mEmail)
                 && mGaiaId.equals(other.mGaiaId);
     }
+
+    /**
+     * Null-checking helper to create {@link Account} from a possibly null {@link CoreAccountInfo}.
+     *
+     * @return {@link Account} for the argument if it is not null, null otherwise.
+     */
+    public static @Nullable Account getAndroidAccountFrom(@Nullable CoreAccountInfo accountInfo) {
+        return accountInfo == null
+                ? null
+                : AccountManagerFacade.createAccountFromName(accountInfo.getEmail());
+    }
+
+    /**
+     * Null-checking helper to get an account id from a possibly null {@link CoreAccountInfo}.
+     *
+     * @return {@link #getId()} for the argument if it is not null, null otherwise.
+     */
+    public static @Nullable CoreAccountId getIdFrom(@Nullable CoreAccountInfo accountInfo) {
+        return accountInfo == null ? null : accountInfo.getId();
+    }
+
+    /**
+     * Null-checking helper to get an email from a possibly null {@link CoreAccountInfo}.
+     *
+     * @return {@link #getEmail()} for the argument if it is not null, null otherwise.
+     */
+    public static @Nullable String getEmailFrom(@Nullable CoreAccountInfo accountInfo) {
+        return accountInfo == null ? null : accountInfo.getEmail();
+    }
+
+    /**
+     * Null-checking helper to get a GaiaId from a possibly null {@link CoreAccountInfo}.
+     *
+     * @return {@link #getGaiaId()} ()} for the argument if it is not null, null otherwise.
+     */
+    public static @Nullable String getGaiaIdFrom(@Nullable CoreAccountInfo accountInfo) {
+        return accountInfo == null ? null : accountInfo.getGaiaId();
+    }
 }

components/signin/public/android/java/src/org/chromium/components/signin/identitymanager/IdentityManager.java

@@ -141,8 +141,7 @@ public class IdentityManager {
      * is available.
      */
     public @Nullable CoreAccountId getPrimaryAccountId() {
-        CoreAccountInfo primaryAccountInfo = getPrimaryAccountInfo();
-        return primaryAccountInfo == null ? null : primaryAccountInfo.getId();
+        return CoreAccountInfo.getIdFrom(getPrimaryAccountInfo());
     }
 
     /**