[Android] Fix thread assert in InvalidationClientService

This CL adds ThreadUtils.runOnUiThread around call to
AccountManagerFacade.getNewAuthToken as this method should be invoked
on UI thread only.

Bug: 759023
Change-Id: I67c05084dca091ab1909549556211f84b8dec9c6
Reviewed-on: https://chromium-review.googlesource.com/702303Reviewed-by: Pavel Yatsuk <pavely@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506769}

components/invalidation/impl/android/java/src/org/chromium/components/invalidation/InvalidationClientService.java

@@ -26,6 +26,7 @@ import org.chromium.base.BuildInfo;
 import org.chromium.base.CollectionUtil;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.components.signin.AccountManagerFacade;
 import org.chromium.components.signin.ChromeSigninController;
@@ -251,19 +252,21 @@ public class InvalidationClientService extends AndroidListener {
             return;
         }
 
-        // Attempt to retrieve a token for the user. This method will also invalidate
-        // invalidAuthToken if it is non-null.
-        AccountManagerFacade.get().getNewAuthToken(account, invalidAuthToken,
-                getOAuth2ScopeWithType(), new AccountManagerFacade.GetAuthTokenCallback() {
-                    @Override
-                    public void tokenAvailable(String token) {
-                        setAuthToken(InvalidationClientService.this.getApplicationContext(),
-                                pendingIntent, token, getOAuth2ScopeWithType());
-                    }
-
-                    @Override
-                    public void tokenUnavailable(boolean isTransientError) {}
-                });
+        ThreadUtils.runOnUiThread(() -> {
+            // Attempt to retrieve a token for the user. This method will also invalidate
+            // invalidAuthToken if it is non-null.
+            AccountManagerFacade.get().getNewAuthToken(account, invalidAuthToken,
+                    getOAuth2ScopeWithType(), new AccountManagerFacade.GetAuthTokenCallback() {
+                        @Override
+                        public void tokenAvailable(String token) {
+                            setAuthToken(InvalidationClientService.this.getApplicationContext(),
+                                    pendingIntent, token, getOAuth2ScopeWithType());
+                        }
+
+                        @Override
+                        public void tokenUnavailable(boolean isTransientError) {}
+                    });
+        });
     }
 
     @Override