Quick Answers: Add browser client

Add the browser client to get Access token.

Bug: b/150034512
Test: Manual Test
Change-Id: Ic3f87ee4299779797005d56daa411b122750bea7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2429528
Commit-Queue: Yue Li <updowndota@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Auto-Submit: Yue Li <updowndota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811079}

ash/public/cpp/BUILD.gn

@@ -241,6 +241,8 @@ component("cpp") {
     "presentation_time_recorder.h",
     "privacy_screen_dlp_helper.cc",
     "privacy_screen_dlp_helper.h",
+    "quick_answers/controller/quick_answers_browser_client.cc",
+    "quick_answers/controller/quick_answers_browser_client.h",
     "quick_answers/controller/quick_answers_controller.cc",
     "quick_answers/controller/quick_answers_controller.h",
     "rounded_corner_decorator.cc",

ash/public/cpp/quick_answers/controller/quick_answers_browser_client.cc

+// Copyright 2020 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 "ash/public/cpp/quick_answers/controller/quick_answers_browser_client.h"
+
+#include "base/check_op.h"
+
+namespace ash {
+
+namespace {
+QuickAnswersBrowserClient* g_instance = nullptr;
+}
+
+QuickAnswersBrowserClient::QuickAnswersBrowserClient() {
+  DCHECK_EQ(nullptr, g_instance);
+  g_instance = this;
+}
+
+QuickAnswersBrowserClient::~QuickAnswersBrowserClient() {
+  DCHECK_EQ(this, g_instance);
+  g_instance = nullptr;
+}
+
+QuickAnswersBrowserClient* QuickAnswersBrowserClient::Get() {
+  return g_instance;
+}
+}  // namespace ash

ash/public/cpp/quick_answers/controller/quick_answers_browser_client.h

+// Copyright 2020 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.
+
+#ifndef ASH_PUBLIC_CPP_QUICK_ANSWERS_CONTROLLER_QUICK_ANSWERS_BROWSER_CLIENT_H_
+#define ASH_PUBLIC_CPP_QUICK_ANSWERS_CONTROLLER_QUICK_ANSWERS_BROWSER_CLIENT_H_
+
+#include <string>
+
+#include "ash/public/cpp/ash_public_export.h"
+#include "base/callback_forward.h"
+
+namespace ash {
+
+// A client class which provides browser access to Quick Answers.
+class ASH_PUBLIC_EXPORT QuickAnswersBrowserClient {
+ public:
+  using GetAccessTokenCallback =
+      base::OnceCallback<void(const std::string& access_token)>;
+
+  QuickAnswersBrowserClient();
+  virtual ~QuickAnswersBrowserClient();
+
+  // Get the instance of |QuickAnswersBrowserClient|.
+  static QuickAnswersBrowserClient* Get();
+
+  // Request for the access token associated with the active user's profile.
+  // Request is handled asynchronously if the token is not available.
+  // AccessTokenCallbacks are invoked as soon as the token if fetched.
+  // If the token is available, AccessTokenCallbacks are invoked
+  // synchronously before RequestAccessToken() returns.
+  virtual void RequestAccessToken(GetAccessTokenCallback callback) = 0;
+};
+
+}  // namespace ash
+
+#endif  // ASH_PUBLIC_CPP_QUICK_ANSWERS_CONTROLLER_QUICK_ANSWERS_BROWSER_CLIENT_H_

chrome/browser/ui/BUILD.gn

@@ -1996,6 +1996,8 @@ static_library("ui") {
       "ash/network/network_state_notifier.h",
       "ash/network/tether_notification_presenter.cc",
       "ash/network/tether_notification_presenter.h",
+      "ash/quick_answers/quick_answers_browser_client_impl.cc",
+      "ash/quick_answers/quick_answers_browser_client_impl.h",
       "ash/screen_orientation_delegate_chromeos.cc",
       "ash/screen_orientation_delegate_chromeos.h",
       "ash/session_controller_client_impl.cc",

chrome/browser/ui/ash/chrome_browser_main_extra_parts_ash.cc

@@ -40,6 +40,7 @@
 #include "chrome/browser/ui/ash/network/mobile_data_notifications.h"
 #include "chrome/browser/ui/ash/network/network_connect_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/network/network_portal_notification_controller.h"
+#include "chrome/browser/ui/ash/quick_answers/quick_answers_browser_client_impl.h"
 #include "chrome/browser/ui/ash/screen_orientation_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/session_controller_client_impl.h"
 #include "chrome/browser/ui/ash/system_tray_client.h"
@@ -125,6 +126,11 @@ void ChromeBrowserMainExtraPartsAsh::PreProfileInit() {
   if (chromeos::features::IsAmbientModeEnabled())
     ambient_client_ = std::make_unique<AmbientClientImpl>();
 
+  if (chromeos::features::IsQuickAnswersEnabled()) {
+    quick_answers_browser_client_ =
+        std::make_unique<QuickAnswersBrowserClientImpl>();
+  }
+
   media_notification_provider_ =
       std::make_unique<MediaNotificationProviderImpl>();
   ash::MediaNotificationProvider::Set(media_notification_provider_.get());

chrome/browser/ui/ash/chrome_browser_main_extra_parts_ash.h

@@ -33,6 +33,7 @@ class MediaClientImpl;
 class MobileDataNotifications;
 class NetworkConnectDelegateChromeOS;
 class NightLightClient;
+class QuickAnswersBrowserClientImpl;
 class ScreenOrientationDelegateChromeos;
 class SessionControllerClientImpl;
 class SystemTrayClient;
@@ -112,6 +113,7 @@ class ChromeBrowserMainExtraPartsAsh : public ChromeBrowserMainExtraParts {
   std::unique_ptr<MobileDataNotifications> mobile_data_notifications_;
   std::unique_ptr<NightLightClient> night_light_client_;
   std::unique_ptr<AmbientClientImpl> ambient_client_;
+  std::unique_ptr<QuickAnswersBrowserClientImpl> quick_answers_browser_client_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainExtraPartsAsh);
 };

chrome/browser/ui/ash/quick_answers/quick_answers_browser_client_impl.cc

+// Copyright 2020 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/ui/ash/quick_answers/quick_answers_browser_client_impl.h"
+
+#include "base/logging.h"
+#include "base/rand_util.h"
+#include "base/time/time.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/signin/identity_manager_factory.h"
+#include "components/account_id/account_id.h"
+#include "components/signin/public/identity_manager/access_token_fetcher.h"
+#include "components/signin/public/identity_manager/access_token_info.h"
+#include "components/signin/public/identity_manager/consent_level.h"
+#include "components/signin/public/identity_manager/identity_manager.h"
+#include "components/signin/public/identity_manager/scope_set.h"
+
+namespace {
+
+constexpr char kCloudTranslationScope[] =
+    "https://www.googleapis.com/auth/cloud-translation";
+
+constexpr base::TimeDelta kMinTokenRefreshDelay =
+    base::TimeDelta::FromMilliseconds(1000);
+constexpr base::TimeDelta kMaxTokenRefreshDelay =
+    base::TimeDelta::FromMilliseconds(60 * 1000);
+
+}  // namespace
+
+QuickAnswersBrowserClientImpl::QuickAnswersBrowserClientImpl() = default;
+
+QuickAnswersBrowserClientImpl::~QuickAnswersBrowserClientImpl() = default;
+
+void QuickAnswersBrowserClientImpl::RequestAccessToken(
+    AccessTokenCallback callback) {
+  if (!access_token_.empty()) {
+    // Return the token if there is enough time to use the access token when
+    // requested.
+    if (expiration_time_ - base::Time::Now() > token_usage_time_buffer_) {
+      std::move(callback).Run(access_token_);
+      return;
+    }
+
+    access_token_.clear();
+    expiration_time_ = base::Time::Now();
+  }
+
+  callbacks_.emplace_back(std::move(callback));
+
+  // There is already pending request.
+  if (access_token_fetcher_)
+    return;
+
+  RefreshAccessToken();
+}
+
+void QuickAnswersBrowserClientImpl::RefreshAccessToken() {
+  auto* profile = ProfileManager::GetActiveUserProfile();
+  DCHECK(profile);
+
+  signin::IdentityManager* identity_manager =
+      IdentityManagerFactory::GetForProfile(profile);
+  DCHECK(identity_manager);
+
+  CoreAccountInfo account_info = identity_manager->GetPrimaryAccountInfo(
+      signin::ConsentLevel::kNotRequired);
+
+  const signin::ScopeSet scopes{kCloudTranslationScope};
+  DCHECK(!access_token_fetcher_);
+  access_token_fetcher_ = identity_manager->CreateAccessTokenFetcherForAccount(
+      account_info.account_id, /*oauth_consumer_name=*/"cros_quick_answers",
+      scopes,
+      base::BindOnce(&QuickAnswersBrowserClientImpl::OnAccessTokenRefreshed,
+                     weak_factory_.GetWeakPtr()),
+      signin::AccessTokenFetcher::Mode::kImmediate);
+}
+
+void QuickAnswersBrowserClientImpl::OnAccessTokenRefreshed(
+    GoogleServiceAuthError error,
+    signin::AccessTokenInfo access_token_info) {
+  // It's safe to delete AccessTokenFetcher from inside its own callback.
+  access_token_fetcher_.reset();
+
+  if (error.state() != GoogleServiceAuthError::NONE) {
+    LOG(ERROR) << "Failed to retrieve token, error: " << error.ToString();
+    RetryRefreshAccessToken();
+    return;
+  }
+
+  VLOG(1) << "Access token fetched.";
+  access_token_ = access_token_info.token;
+  expiration_time_ = access_token_info.expiration_time;
+  NotifyAccessTokenRefreshed();
+}
+
+void QuickAnswersBrowserClientImpl::RetryRefreshAccessToken() {
+  base::TimeDelta backoff_delay =
+      std::min(kMinTokenRefreshDelay *
+                   (1 << (token_refresh_error_backoff_factor_ - 1)),
+               kMaxTokenRefreshDelay) +
+      base::RandDouble() * kMinTokenRefreshDelay;
+
+  if (backoff_delay < kMaxTokenRefreshDelay)
+    ++token_refresh_error_backoff_factor_;
+
+  token_refresh_timer_.Start(
+      FROM_HERE, backoff_delay,
+      base::BindOnce(&QuickAnswersBrowserClientImpl::RefreshAccessToken,
+                     weak_factory_.GetWeakPtr()));
+}
+
+void QuickAnswersBrowserClientImpl::NotifyAccessTokenRefreshed() {
+  std::vector<AccessTokenCallback> callbacks;
+  callbacks.swap(callbacks_);
+
+  for (auto& callback : callbacks)
+    std::move(callback).Run(access_token_);
+}

chrome/browser/ui/ash/quick_answers/quick_answers_browser_client_impl.h

+// Copyright 2020 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.
+
+#ifndef CHROME_BROWSER_UI_ASH_QUICK_ANSWERS_QUICK_ANSWERS_BROWSER_CLIENT_IMPL_H_
+#define CHROME_BROWSER_UI_ASH_QUICK_ANSWERS_QUICK_ANSWERS_BROWSER_CLIENT_IMPL_H_
+
+#include <string>
+#include <vector>
+
+#include "ash/public/cpp/quick_answers/controller/quick_answers_browser_client.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+
+class GoogleServiceAuthError;
+
+namespace signin {
+class AccessTokenFetcher;
+struct AccessTokenInfo;
+}  // namespace signin
+
+// A client class which provides browser access to quick answers.
+class QuickAnswersBrowserClientImpl : public ash::QuickAnswersBrowserClient {
+ public:
+  using AccessTokenCallback =
+      base::OnceCallback<void(const std::string& access_token)>;
+
+  QuickAnswersBrowserClientImpl();
+
+  QuickAnswersBrowserClientImpl(const QuickAnswersBrowserClientImpl&) = delete;
+  QuickAnswersBrowserClientImpl& operator=(
+      const QuickAnswersBrowserClientImpl&) = delete;
+
+  ~QuickAnswersBrowserClientImpl() override;
+
+  // ash::QuickAnswersBrowserClient:
+  void RequestAccessToken(AccessTokenCallback callback) override;
+
+ private:
+  void RefreshAccessToken();
+  void OnAccessTokenRefreshed(GoogleServiceAuthError error,
+                              signin::AccessTokenInfo access_token_info);
+  void RetryRefreshAccessToken();
+  void NotifyAccessTokenRefreshed();
+
+  std::string access_token_;
+
+  std::unique_ptr<signin::AccessTokenFetcher> access_token_fetcher_;
+
+  // The expiration time of the |access_token_|.
+  base::Time expiration_time_;
+
+  // The buffer time to use the access token.
+  base::TimeDelta token_usage_time_buffer_ = base::TimeDelta::FromMinutes(1);
+
+  base::OneShotTimer token_refresh_timer_;
+  int token_refresh_error_backoff_factor_ = 1;
+
+  std::vector<AccessTokenCallback> callbacks_;
+
+  base::WeakPtrFactory<QuickAnswersBrowserClientImpl> weak_factory_{this};
+};
+
+#endif  // CHROME_BROWSER_UI_ASH_QUICK_ANSWERS_QUICK_ANSWERS_BROWSER_CLIENT_IMPL_H_