[Sync] Improve test to use content resolver

This more accurately simulates a user making changes through the Android
sync settings in an end-to-end way.

BUG=480604

Review URL: https://codereview.chromium.org/1137073002

Cr-Commit-Position: refs/heads/master@{#329905}

chrome/android/sync_shell/javatests/src/org/chromium/chrome/browser/sync/SyncTest.java

@@ -130,17 +130,20 @@ public class SyncTest extends SyncTestBase {
 
     @LargeTest
     @Feature({"Sync"})
-    public void testDisableAndEnableSync() throws InterruptedException {
+    public void testDisableAndEnableSyncThroughAndroid() throws InterruptedException {
         setupTestAccountAndSignInToSync(CLIENT_ID);
+        SyncTestUtil.ensureSyncInitialized(mContext);
+
         Account account =
                 AccountManagerHelper.createAccountFromName(SyncTestUtil.DEFAULT_TEST_ACCOUNT);
+        String authority = AndroidSyncSettings.get(mContext).getContractAuthority();
 
         // Disabling Android sync should turn Chrome sync engine off.
-        AndroidSyncSettings.get(mContext).disableChromeSync();
+        mSyncContentResolver.setSyncAutomatically(account, authority, false);
         SyncTestUtil.verifySyncIsDisabled(mContext, account);
 
         // Enabling Android sync should turn Chrome sync engine on.
-        AndroidSyncSettings.get(mContext).enableChromeSync();
+        mSyncContentResolver.setSyncAutomatically(account, authority, true);
         SyncTestUtil.ensureSyncInitialized(mContext);
         SyncTestUtil.verifySignedInWithAccount(mContext, account);
     }

chrome/android/sync_shell/javatests/src/org/chromium/chrome/browser/sync/SyncTestBase.java

@@ -38,6 +38,7 @@ public class SyncTestBase extends ChromeShellTestBase {
     protected SyncController mSyncController;
     protected FakeServerHelper mFakeServerHelper;
     protected ProfileSyncService mProfileSyncService;
+    protected MockSyncContentResolverDelegate mSyncContentResolver;
 
     @Override
     protected void setUp() throws Exception {
@@ -109,10 +110,9 @@ public class SyncTestBase extends ChromeShellTestBase {
     }
 
     private void setUpMockAndroidSyncSettings() {
-        MockSyncContentResolverDelegate syncContentResolverDelegate =
-                new MockSyncContentResolverDelegate();
-        syncContentResolverDelegate.setMasterSyncAutomatically(true);
-        AndroidSyncSettings.overrideForTests(mContext, syncContentResolverDelegate);
+        mSyncContentResolver = new MockSyncContentResolverDelegate();
+        mSyncContentResolver.setMasterSyncAutomatically(true);
+        AndroidSyncSettings.overrideForTests(mContext, mSyncContentResolver);
     }
 
     protected void setupTestAccountAndSignInToSync(