Remove all blimp client code.

blimp/client/support/session/blimp_default_identity_provider.cc

-// 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.
-
-#include "blimp/client/support/session/blimp_default_identity_provider.h"
-
-#include "google_apis/gaia/oauth2_token_service.h"
-
-namespace blimp {
-namespace client {
-namespace {
-constexpr char kDummyAccountId[] = "DummyAccountId";
-}  // namespace
-
-BlimpDefaultIdentityProvider::BlimpDefaultIdentityProvider() = default;
-
-BlimpDefaultIdentityProvider::~BlimpDefaultIdentityProvider() = default;
-
-std::string BlimpDefaultIdentityProvider::GetActiveUsername() {
-  return kDummyAccountId;
-}
-
-std::string BlimpDefaultIdentityProvider::GetActiveAccountId() {
-  return kDummyAccountId;
-}
-
-OAuth2TokenService* BlimpDefaultIdentityProvider::GetTokenService() {
-  return nullptr;
-}
-
-bool BlimpDefaultIdentityProvider::RequestLogin() {
-  return false;
-}
-
-}  // namespace client
-}  // namespace blimp