Fix tests calling methods on the wrong thread.

chrome/android/javatests/src/org/chromium/chrome/browser/ChromeBackupIntegrationTest.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser;
 
 import android.accounts.Account;
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.Build;
 import android.test.suitebuilder.annotation.SmallTest;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.StreamUtil;
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.base.test.util.MinAndroidSdkLevel;
 import org.chromium.chrome.browser.firstrun.FirstRunSignInProcessor;
 import org.chromium.chrome.browser.firstrun.FirstRunStatus;
 import org.chromium.chrome.browser.init.ChromeBrowserInitializer;
 import org.chromium.chrome.browser.signin.AccountIdProvider;
 import org.chromium.chrome.test.ChromeTabbedActivityTestBase;
 import org.chromium.sync.signin.AccountManagerHelper;
 import org.chromium.sync.signin.ChromeSigninController;
 import org.chromium.sync.test.util.MockAccountManager;
@@ skipping 58 matching lines @@
 
         mTargetContext = getInstrumentation().getTargetContext();
 
         // Create a mock account manager. Although this isn't used by ChromeBackupAgent it is used
         // when we test the result by starting Chrome.
         ChromeBackupAgent.allowChromeApplicationForTesting();
         Account account = new Account(TEST_ACCOUNT_1, GOOGLE_ACCOUNT_TYPE);
         MockAccountManager accountManager =
                 new MockAccountManager(mTargetContext, getInstrumentation().getContext(), account);
         AccountManagerHelper.overrideAccountManagerHelperForTests(mTargetContext, accountManager);
-        AccountIdProvider.setInstanceForTest(new MockAccountIdProvider());
+
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                AccountIdProvider.setInstanceForTest(new MockAccountIdProvider());
+            }
+        });
     }
 
     @SmallTest
     @MinAndroidSdkLevel(Build.VERSION_CODES.LOLLIPOP)
     public void testSimpleRestore() throws InterruptedException, IOException {
 
         // Fake having previously gone through FRE and signed in.
         SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
         SharedPreferences.Editor preferenceEditor = prefs.edit();
         preferenceEditor.putBoolean(FirstRunStatus.FIRST_RUN_FLOW_COMPLETE, true);
@@ skipping 88 matching lines @@
             int fileLength = (int) prefsFile.length();
             byte[] inputBuffer = new byte[fileLength];
             assertEquals(fileLength, prefsFileReader.read(inputBuffer));
             return new String(inputBuffer, "UTF-8");
         } finally {
             StreamUtil.closeQuietly(prefsFileReader);
         }
     }
 
 }