Add SyncAuthProvider interface and implementation

chrome/browser/sync/profile_sync_auth_provider.cc

+// Copyright 2014 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 "chrome/browser/sync/profile_sync_auth_provider.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/single_thread_task_runner.h"
+#include "base/thread_task_runner_handle.h"
+#include "components/signin/core/browser/profile_oauth2_token_service.h"
+#include "google_apis/gaia/gaia_constants.h"
+
+// This is thin proxy class for forwarding calls between sync and UI threads.
+// The main purpose is to hide the fact that ProfileSyncAuthProvider and
+// SyncThreadProxy have independent lifetimes. If ProfileSyncAuthProvider is
+// destroyed first calls to RequestAccessToken will never complete. This is fine
+// since sync thread is not blocked and is in the process of shutdown anyway.
+class ProfileSyncAuthProvider::SyncThreadProxy
+    : public syncer::SyncAuthProvider,
+      public base::NonThreadSafe {
+ public:
+  SyncThreadProxy(
+      base::WeakPtr<ProfileSyncAuthProvider> provider_impl,
+      scoped_refptr<base::SingleThreadTaskRunner> provider_task_runner);
+
+  // syncer::SyncAuthProvider implementation.
+  virtual void RequestAccessToken(
+      const RequestTokenCallback& callback) OVERRIDE;
+  virtual void InvalidateAccessToken(const std::string& token) OVERRIDE;
+
+ private:
+  base::WeakPtr<ProfileSyncAuthProvider> provider_impl_;
+  scoped_refptr<base::SingleThreadTaskRunner> provider_task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(SyncThreadProxy);
+};
+
+ProfileSyncAuthProvider::SyncThreadProxy::SyncThreadProxy(
+    base::WeakPtr<ProfileSyncAuthProvider> provider_impl,
+    scoped_refptr<base::SingleThreadTaskRunner> provider_task_runner)
+    : provider_impl_(provider_impl),
+      provider_task_runner_(provider_task_runner) {
+  DetachFromThread();

[tim (not reviewing), 2014/04/29 22:12:11]

Explain this?

[pavely, 2014/04/30 19:46:40]

SyncThreadProxy is created on UI thread but used only on sync thread.
ThreadCheckerImpl remembers which thread it was constructed on.
DetachFromThread is the way to rebind it to different thread.

I'll add comment.
On 2014/04/29 22:12:11, timsteele wrote:

+}
+
+void ProfileSyncAuthProvider::SyncThreadProxy::RequestAccessToken(
+    const RequestTokenCallback& callback) {
+  DCHECK(CalledOnValidThread());
+  provider_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&ProfileSyncAuthProvider::RequestAccessToken,
+                 provider_impl_,
+                 callback,
+                 base::ThreadTaskRunnerHandle::Get()));
+}
+
+void ProfileSyncAuthProvider::SyncThreadProxy::InvalidateAccessToken(
+    const std::string& token) {
+  DCHECK(CalledOnValidThread());
+  provider_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&ProfileSyncAuthProvider::InvalidateAccessToken,
+                 provider_impl_,
+                 token));
+}
+
+ProfileSyncAuthProvider::ProfileSyncAuthProvider(
+    ProfileOAuth2TokenService* token_service,
+    const std::string& account_id,
+    const std::string& scope)
+    : OAuth2TokenService::Consumer("sync_auth_provider"),

[tim (not reviewing), 2014/04/29 22:12:11]

nit - make string a constant.

[pavely, 2014/04/30 19:46:40]

All other calls to OAuth2TokenService::Consumer just pass string literal. The
reason is that this string is only used to display token requests on
about:signin-internals. It is never used multiple times in the code or compared
to other values or used as key into collection.

I can still change it to constant if you want. Let me know.

+      token_service_(token_service),
+      account_id_(account_id),
+      weak_factory_(this) {
+  oauth2_scope_.insert(scope);
+}
+
+ProfileSyncAuthProvider::~ProfileSyncAuthProvider() {
+  DCHECK(CalledOnValidThread());
+}
+
+void ProfileSyncAuthProvider::RequestAccessToken(
+    const syncer::SyncAuthProvider::RequestTokenCallback& callback,
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
+  DCHECK(CalledOnValidThread());
+  if (access_token_request_ != NULL) {
+    // If there is already pending request report it as cancelled.
+    GoogleServiceAuthError error(GoogleServiceAuthError::REQUEST_CANCELED);
+    RespondToTokenRequest(error, std::string());
+  }
+  request_token_callback_ = callback;
+  callback_task_runner_ = task_runner;
+  access_token_request_ =
+      token_service_->StartRequest(account_id_, oauth2_scope_, this);
+}
+
+void ProfileSyncAuthProvider::OnGetTokenSuccess(
+    const OAuth2TokenService::Request* request,
+    const std::string& access_token,
+    const base::Time& expiration_time) {
+  DCHECK_EQ(access_token_request_, request);
+  RespondToTokenRequest(GoogleServiceAuthError::AuthErrorNone(), access_token);
+}
+
+void ProfileSyncAuthProvider::OnGetTokenFailure(
+    const OAuth2TokenService::Request* request,
+    const GoogleServiceAuthError& error) {
+  DCHECK_EQ(access_token_request_, request);
+  RespondToTokenRequest(error, std::string());
+}
+
+void ProfileSyncAuthProvider::RespondToTokenRequest(
+    const GoogleServiceAuthError& error,
+    const std::string& token) {
+  DCHECK(CalledOnValidThread());
+  callback_task_runner_->PostTask(
+      FROM_HERE, base::Bind(request_token_callback_, error, token));
+  access_token_request_.reset();
+  request_token_callback_.Reset();
+  callback_task_runner_ = NULL;
+}
+
+void ProfileSyncAuthProvider::InvalidateAccessToken(const std::string& token) {
+  DCHECK(CalledOnValidThread());
+  token_service_->InvalidateToken(account_id_, oauth2_scope_, token);
+}
+
+scoped_ptr<syncer::SyncAuthProvider>
+ProfileSyncAuthProvider::CreateProviderForSyncThread() {
+  DCHECK(CalledOnValidThread());
+  scoped_ptr<syncer::SyncAuthProvider> auth_provider(new SyncThreadProxy(
+      weak_factory_.GetWeakPtr(), base::ThreadTaskRunnerHandle::Get()));
+  return auth_provider.Pass();
+}