AccountManagerを利用する ref: http://qiita.com/nein37/items/25ba6e5176118fae5f13

AndroidManifest.xml

    <uses-permission android:name="android.permission.GET_ACCOUNTS"/>
    <uses-permission android:name="android.permission.USE_CREDENTIALS"/>

file1.java

    AccountManager manager = AccountManager.get(context);
    Account[] accountArray = manager.getAccounts();

file10.java

        AccountManager manager = AccountManager.get(this);
        manager.getAuthToken(new Account("user@gmail.com", "com.google"), "mail", null,
            this, new AccountManagerCallback<Bundle>() {
                @Override
                public void run(AccountManagerFuture<Bundle> future) {
                    Bundle bundle = null;
                    try {
                        bundle = future.getResult();
                        String accountName = bundle.getString(AccountManager.KEY_ACCOUNT_NAME);
                        String accountType = bundle.getString(AccountManager.KEY_ACCOUNT_TYPE);
                        String authToken = bundle.getString(AccountManager.KEY_AUTHTOKEN);
                        Toast.makeText(MyActivity.this,authToken,Toast.LENGTH_SHORT).show();
                    } catch (OperationCanceledException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    } catch (AuthenticatorException e) {
                        e.printStackTrace();
                    }
                }
            }, null);

file11.java

AccountManager manager = AccountManager.get(this);
manager.invalidateAuthToken("com.google",TOKEN);

file2.java

    AccountManager manager = AccountManager.get(context);
    Account[] accountArray = manager.getAccountsByType("com.google");

file3.java

// Get the account list, and pick the first one
final String ACCOUNT_TYPE_GOOGLE = "com.google";
final String[] FEATURES_MAIL = {
        "service_mail"
};
AccountManager.get(this).getAccountsByTypeAndFeatures(ACCOUNT_TYPE_GOOGLE, FEATURES_MAIL,
        new AccountManagerCallback() {
            @Override
            public void run(AccountManagerFuture future) {
                Account[] accounts = null;
                try {
                    accounts = future.getResult();
                    if (accounts != null && accounts.length > 0) {
                        String selectedAccount = accounts[0].name;
                        queryLabels(selectedAccount);
                    }
ru

                } catch (OperationCanceledException oce) {
                    // TODO: handle exception
                } catch (IOException ioe) {
                    // TODO: handle exception
                } catch (AuthenticatorException ae) {
                    // TODO: handle exception
                }
            }
        }, null /* handler */);

file4.java

 @Override
    public void onClick(View v) {

        Intent intent = AccountManager.get(this).newChooseAccountIntent(null, null, new String[] {
                "com.google"
        }, false, null,
                null, null, null);
        startActivityForResult(intent, REQUEST_CODE);

    }

    @Override
    protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        {
            if (requestCode == REQUEST_CODE && resultCode == Activity.RESULT_OK)
                Toast.makeText(this, data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME),
                        Toast.LENGTH_SHORT).show();
        }
    }

file6.java

        AccountManager manager = AccountManager.get(this);
        manager.addAccount("com.google", "mail", null, null, activity,
                new AccountManagerCallback<Bundle>() {
                    @Override
                    public void run(AccountManagerFuture<Bundle> future) {
                        try {
                            Bundle bundle = future.getResult();
                            String accountName = bundle.getString(AccountManager.KEY_ACCOUNT_NAME);
                        } catch (OperationCanceledException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        } catch (AuthenticatorException e) {
                            e.printStackTrace();
                        }
                    }
                }, null);

file7.java

    AccountManager manager = AccountManager.get(this);
    manager.removeAccount(new Account("user@gmail.com","com.google"),
        new AccountManagerCallback<Boolean>() {
            @Override
            public void run(AccountManagerFuture<Boolean> future) {
                try {
                  boolean result = future.getResult(); 
                } catch (OperationCanceledException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (AuthenticatorException e) {
                    e.printStackTrace();
                }
            }
        }, null);

file8.java

        AccountManager manager = AccountManager.get(this);
        manager.clearPassword(new Account("user@gmail.com","com.google"));