[Signin][Android] Assert that sign-in is allowed in SigninManager.signIn

Adds an assert to verify that sign-in is allowed before starting it.
To fix tests broken by this assert, this CL also adds an explicit
ExternalAuthUtils param to SigninManager.
This is necessary for the upcoming removal of
AccountIdProvider.canBeUsed.

Bug: 914920
Change-Id: Ib2ddd446446539fc45534818d30b5e6dab4fef73
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1985006Reviewed-by: Tanmoy Mollik <triploblastic@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728269}

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninManager.java

@@ -172,6 +172,7 @@ public class SigninManager
     private final IdentityManager mIdentityManager;
     private final IdentityMutator mIdentityMutator;
     private final AndroidSyncSettings mAndroidSyncSettings;
+    private final ExternalAuthUtils mExternalAuthUtils;
     private final ObserverList<SignInStateObserver> mSignInStateObservers = new ObserverList<>();
     private final ObserverList<SignInAllowedObserver> mSignInAllowedObservers =
             new ObserverList<>();
@@ -212,13 +213,13 @@ public class SigninManager
         assert identityManager != null;
         assert identityMutator != null;
         return new SigninManager(nativeSigninManagerAndroid, accountTrackerService, identityManager,
-                identityMutator, AndroidSyncSettings.get());
+                identityMutator, AndroidSyncSettings.get(), ExternalAuthUtils.getInstance());
     }
 
     @VisibleForTesting
     SigninManager(long nativeSigninManagerAndroid, AccountTrackerService accountTrackerService,
             IdentityManager identityManager, IdentityMutator identityMutator,
-            AndroidSyncSettings androidSyncSettings) {
+            AndroidSyncSettings androidSyncSettings, ExternalAuthUtils externalAuthUtils) {
         ThreadUtils.assertOnUiThread();
         assert androidSyncSettings != null;
         mNativeSigninManagerAndroid = nativeSigninManagerAndroid;
@@ -226,6 +227,7 @@ public class SigninManager
         mIdentityManager = identityManager;
         mIdentityMutator = identityMutator;
         mAndroidSyncSettings = androidSyncSettings;
+        mExternalAuthUtils = externalAuthUtils;
 
         mSigninAllowedByPolicy =
                 SigninManagerJni.get().isSigninAllowedByPolicy(mNativeSigninManagerAndroid);
@@ -381,6 +383,7 @@ public class SigninManager
     // TODO(crbug.com/1002056) SigninManager.Signin should use CoreAccountInfo as a parameter.
     public void signIn(@SigninAccessPoint int accessPoint, Account account,
             @Nullable SignInCallback callback) {
+        assert isSignInAllowed() : "Sign-in isn't allowed!";
         if (account == null) {
             Log.w(TAG, "Ignoring sign-in request due to null account.");
             if (callback != null) callback.onSignInAborted();
@@ -669,7 +672,7 @@ public class SigninManager
     }
 
     private boolean isGooglePlayServicesPresent() {
-        return !ExternalAuthUtils.getInstance().isGooglePlayServicesMissing(
+        return !mExternalAuthUtils.isGooglePlayServicesMissing(
                 ContextUtils.getApplicationContext());
     }
 

chrome/android/junit/src/org/chromium/chrome/browser/signin/SigninManagerTest.java

@@ -32,6 +32,7 @@ import org.robolectric.annotation.Config;
 import org.chromium.base.test.BaseRobolectricTestRunner;
 import org.chromium.base.test.DisableNativeTestRule;
 import org.chromium.base.test.util.JniMocker;
+import org.chromium.chrome.browser.externalauth.ExternalAuthUtils;
 import org.chromium.components.signin.AccountManagerFacade;
 import org.chromium.components.signin.AccountTrackerService;
 import org.chromium.components.signin.base.CoreAccountId;
@@ -80,9 +81,14 @@ public class SigninManagerTest {
 
         AndroidSyncSettings androidSyncSettings = mock(AndroidSyncSettings.class);
 
+        ExternalAuthUtils externalAuthUtils = mock(ExternalAuthUtils.class);
+        // Pretend Google Play services are available as it is required for the sign-in
+        doReturn(false).when(externalAuthUtils).isGooglePlayServicesMissing(any());
+
         doReturn(null).when(mIdentityManager).getPrimaryAccountId();
-        mSigninManager = new SigninManager(0 /* nativeSigninManagerAndroid */,
-                mAccountTrackerService, mIdentityManager, mIdentityMutator, androidSyncSettings);
+        mSigninManager =
+                new SigninManager(0 /* nativeSigninManagerAndroid */, mAccountTrackerService,
+                        mIdentityManager, mIdentityMutator, androidSyncSettings, externalAuthUtils);
 
         mAccount = new CoreAccountInfo(new CoreAccountId("gaia-id-user"),
                 AccountManagerFacade.createAccountFromName("user@domain.com"), "gaia-id-user");