[CrOS PhoneHub] Get Browser tab metadata including favicons.

Creates a helper class that gets the metadata needed to return
a vector of the latest visited BrowserTabMetadata to the caller.

Creates a fake version that can be used for unit tests of
callers to this class.

Note the class requires a FaviconService to be passed in the ctor.

Bug: 1106937
Change-Id: Ibe669cc337190025c59d536f36450c054731e14f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2424513
Commit-Queue: Regan Hsu <hsuregan@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812274}

chrome/browser/chromeos/BUILD.gn

@@ -234,6 +234,7 @@ source_set("chromeos") {
     "//components/drive:drive_chromeos",
     "//components/enterprise",
     "//components/exo",
+    "//components/favicon/core",
     "//components/feedback",
     "//components/flags_ui",
     "//components/gcm_driver",
@@ -283,6 +284,7 @@ source_set("chromeos") {
     "//components/sync",
     "//components/sync_device_info",
     "//components/sync_preferences",
+    "//components/sync_sessions",
     "//components/tracing:startup_tracing",
     "//components/translate/core/browser",
     "//components/ukm/content",
@@ -1936,6 +1938,8 @@ source_set("chromeos") {
     "ownership/owner_settings_service_chromeos.h",
     "ownership/owner_settings_service_chromeos_factory.cc",
     "ownership/owner_settings_service_chromeos_factory.h",
+    "phonehub/browser_tabs_metadata_fetcher_impl.cc",
+    "phonehub/browser_tabs_metadata_fetcher_impl.h",
     "phonehub/phone_hub_manager_factory.cc",
     "phonehub/phone_hub_manager_factory.h",
     "platform_keys/extension_platform_keys_service.cc",
@@ -3432,6 +3436,7 @@ source_set("unit_tests") {
     "night_light/night_light_client_unittest.cc",
     "note_taking_helper_unittest.cc",
     "ownership/owner_settings_service_chromeos_unittest.cc",
+    "phonehub/browser_tabs_metadata_fetcher_impl_unittest.cc",
     "platform_keys/key_permissions/key_permissions_service_impl_unittest.cc",
     "plugin_vm/mock_plugin_vm_manager.cc",
     "plugin_vm/mock_plugin_vm_manager.h",
@@ -3774,6 +3779,7 @@ source_set("unit_tests") {
     "//components/drive",
     "//components/drive:test_support",
     "//components/exo",
+    "//components/favicon/core/test:test_support",
     "//components/invalidation/impl:test_support",
     "//components/invalidation/public",
     "//components/keyed_service/content",
@@ -3788,9 +3794,11 @@ source_set("unit_tests") {
     "//components/resources",
     "//components/services/app_service/public/cpp:test_support",
     "//components/session_manager/core",
+    "//components/sessions:test_support",
     "//components/signin/public/identity_manager:test_support",
     "//components/sync",
     "//components/sync_preferences",
+    "//components/sync_sessions",
     "//components/user_prefs",
     "//components/variations:test_support",
     "//content/test:test_support",

chrome/browser/chromeos/phonehub/DEPS

+include_rules = [
+  "+components/favicon",
+  "+components/sessions/core",
+  "+components/sync_sessions",
+  "+third_party/skia/include/core",
+]

chrome/browser/chromeos/phonehub/browser_tabs_metadata_fetcher_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/chromeos/phonehub/browser_tabs_metadata_fetcher_impl.h"
+
+#include "base/barrier_closure.h"
+#include "components/favicon/core/favicon_service.h"
+#include "components/sync_sessions/synced_session.h"
+
+namespace chromeos {
+namespace phonehub {
+namespace {
+
+std::vector<BrowserTabsModel::BrowserTabMetadata>
+GetSortedMetadataWithoutFavicons(const sync_sessions::SyncedSession* session) {
+  std::vector<BrowserTabsModel::BrowserTabMetadata> browser_tab_metadata;
+
+  using WindowPair =
+      std::pair<const SessionID,
+                std::unique_ptr<sync_sessions::SyncedSessionWindow>>;
+  for (const WindowPair& window_pair : session->windows) {
+    const sessions::SessionWindow& window = window_pair.second->wrapped_window;
+    for (const std::unique_ptr<sessions::SessionTab>& tab : window.tabs) {
+      int selected_index = tab->normalized_navigation_index();
+      const sessions::SerializedNavigationEntry& current_navigation =
+          tab->navigations.at(selected_index);
+
+      GURL tab_url = current_navigation.virtual_url();
+
+      // If the url is incorrectly formatted, or is empty, do not proceed with
+      // storing its metadata.
+      if (!tab_url.is_valid())
+        continue;
+
+      const base::string16& title = current_navigation.title();
+      const base::Time last_accessed_timestamp = tab->timestamp;
+      browser_tab_metadata.emplace_back(tab_url, title, last_accessed_timestamp,
+                                        gfx::Image());
+    }
+  }
+
+  // Sorts the |browser_tab_metadata| from most recently visited to least
+  // recently visited.
+  std::sort(browser_tab_metadata.begin(), browser_tab_metadata.end());
+
+  // At most |kMaxMostRecentTabs| tab metadata can be displayed.
+  size_t num_tabs_to_display = std::min(browser_tab_metadata.size(),
+                                        BrowserTabsModel::kMaxMostRecentTabs);
+  return std::vector<BrowserTabsModel::BrowserTabMetadata>(
+      browser_tab_metadata.begin(),
+      browser_tab_metadata.begin() + num_tabs_to_display);
+}
+
+}  // namespace
+
+BrowserTabsMetadataFetcherImpl::BrowserTabsMetadataFetcherImpl(
+    favicon::FaviconService* favicon_service)
+    : favicon_service_(favicon_service) {}
+
+BrowserTabsMetadataFetcherImpl::~BrowserTabsMetadataFetcherImpl() = default;
+
+void BrowserTabsMetadataFetcherImpl::Fetch(
+    const sync_sessions::SyncedSession* session,
+    base::OnceCallback<void(BrowserTabsMetadataResponse)> callback) {
+  // A new fetch was made, return a base::nullopt to the previous |callback_|.
+  if (!callback_.is_null()) {
+    weak_ptr_factory_.InvalidateWeakPtrs();
+    favicon_tracker_.TryCancelAll();
+    std::move(callback_).Run(base::nullopt);
+  }
+
+  results_ = GetSortedMetadataWithoutFavicons(session);
+  callback_ = std::move(callback);
+
+  // When |barrier| is run |num_tabs_to_display| times, it will run
+  // |OnAllFaviconsFetched|.
+  base::RepeatingClosure barrier = base::BarrierClosure(
+      results_.size(),
+      base::BindOnce(&BrowserTabsMetadataFetcherImpl::OnAllFaviconsFetched,
+                     weak_ptr_factory_.GetWeakPtr()));
+
+  for (size_t i = 0; i < results_.size(); ++i) {
+    favicon_service_->GetFaviconImageForPageURL(
+        results_[i].url,
+        base::BindOnce(&BrowserTabsMetadataFetcherImpl::OnFaviconReady,
+                       weak_ptr_factory_.GetWeakPtr(), i, barrier),
+        &favicon_tracker_);
+  }
+}
+
+void BrowserTabsMetadataFetcherImpl::OnAllFaviconsFetched() {
+  std::move(callback_).Run(std::move(results_));
+}
+
+void BrowserTabsMetadataFetcherImpl::OnFaviconReady(
+    size_t index_in_results,
+    base::OnceClosure done_closure,
+    const favicon_base::FaviconImageResult& favicon_image_result) {
+  DCHECK(index_in_results < results_.size());
+
+  results_[index_in_results].favicon = std::move(favicon_image_result.image);
+  std::move(done_closure).Run();
+}
+
+}  // namespace phonehub
+}  // namespace chromeos

chrome/browser/chromeos/phonehub/browser_tabs_metadata_fetcher_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_CHROMEOS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_IMPL_H_
+#define CHROME_BROWSER_CHROMEOS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_IMPL_H_
+
+#include "base/memory/weak_ptr.h"
+#include "base/task/cancelable_task_tracker.h"
+#include "chromeos/components/phonehub/browser_tabs_metadata_fetcher.h"
+
+namespace favicon_base {
+struct FaviconImageResult;
+}  // namespace favicon_base
+
+namespace favicon {
+class FaviconService;
+}  // namespace favicon
+
+namespace chromeos {
+namespace phonehub {
+
+// BrowserTabsMetadataFetcher implementation. First, a vector containing
+// metadata of the most recently visited tab to least recently visited is
+// created. The metadata is stored from data provided by a SyncedSession. After
+// the ordered vector is created, the FaviconService is used to asynchronously
+// fetch favicon images for the most recently visited tabs. Once all the
+// favicons for the most recently visited tabs (up to
+// BrowserTabsModel::kMaxMostRecentTabs) have been fetched, |results_| is
+// invoked with the callback passed to the class.
+class BrowserTabsMetadataFetcherImpl : public BrowserTabsMetadataFetcher {
+ public:
+  explicit BrowserTabsMetadataFetcherImpl(
+      favicon::FaviconService* favicon_service);
+  ~BrowserTabsMetadataFetcherImpl() override;
+
+  // BrowserTabsMetadataFetcher:
+  void Fetch(
+      const sync_sessions::SyncedSession* session,
+      base::OnceCallback<void(BrowserTabsMetadataResponse)> callback) override;
+
+ private:
+  void OnAllFaviconsFetched();
+  void OnFaviconReady(
+      size_t index_in_results,
+      base::OnceClosure done_closure,
+      const favicon_base::FaviconImageResult& favicon_image_result);
+
+  favicon::FaviconService* const favicon_service_;
+  std::vector<BrowserTabsModel::BrowserTabMetadata> results_;
+  base::OnceCallback<void(BrowserTabsMetadataResponse)> callback_;
+
+  // Used to track a requested favicon.
+  base::CancelableTaskTracker favicon_tracker_;
+
+  base::WeakPtrFactory<BrowserTabsMetadataFetcherImpl> weak_ptr_factory_{this};
+};
+
+}  // namespace phonehub
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_IMPL_H_

chromeos/components/phonehub/BUILD.gn

@@ -8,6 +8,7 @@ assert(is_chromeos, "Phone Hub is Chrome OS only")
 
 static_library("phonehub") {
   sources = [
+    "browser_tabs_metadata_fetcher.h",
     "browser_tabs_model.cc",
     "browser_tabs_model.h",
     "connection_manager.cc",
@@ -121,6 +122,8 @@ static_library("test_support") {
   testonly = true
 
   sources = [
+    "fake_browser_tabs_metadata_fetcher.cc",
+    "fake_browser_tabs_metadata_fetcher.h",
     "fake_connection_manager.cc",
     "fake_connection_manager.h",
     "fake_message_receiver.h",

chromeos/components/phonehub/browser_tabs_metadata_fetcher.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 CHROMEOS_COMPONENTS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_H_
+#define CHROMEOS_COMPONENTS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_H_
+
+#include <vector>
+#include "base/callback.h"
+#include "chromeos/components/phonehub/browser_tabs_model.h"
+
+namespace sync_sessions {
+struct SyncedSession;
+}  // namespace sync_sessions
+
+namespace chromeos {
+namespace phonehub {
+
+// Used to collect the most recently visited tab metadata from a
+// sync_sessions::SyncedSession, fetch their respective favicon images, and
+// return a list of BrowserTabMetadata to its caller.
+class BrowserTabsMetadataFetcher {
+ public:
+  virtual ~BrowserTabsMetadataFetcher() = default;
+
+  BrowserTabsMetadataFetcher(const BrowserTabsMetadataFetcher&) = delete;
+  BrowserTabsMetadataFetcher& operator=(const BrowserTabsMetadataFetcher&) =
+      delete;
+
+  using BrowserTabsMetadataResponse =
+      base::Optional<std::vector<BrowserTabsModel::BrowserTabMetadata>>;
+
+  // Fetches the metadata of the most recently visited tabs. Only one fetch is
+  // possible at a given time, and if a new fetch is started when another is
+  // already in progress, the previous fetch will be passed a base::nullopt.
+  virtual void Fetch(
+      const sync_sessions::SyncedSession* session,
+      base::OnceCallback<void(BrowserTabsMetadataResponse)> callback) = 0;
+
+ protected:
+  BrowserTabsMetadataFetcher() = default;
+};
+
+}  // namespace phonehub
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_H_

chromeos/components/phonehub/browser_tabs_model.cc

@@ -26,9 +26,10 @@ BrowserTabsModel::BrowserTabMetadata::BrowserTabMetadata(
 
 bool BrowserTabsModel::BrowserTabMetadata::operator==(
     const BrowserTabMetadata& other) const {
+  // The favicon is not compared because equality of gfx::Image is defined
+  // by the same storage space rather than the image itself.
   return url == other.url && title == other.title &&
-         last_accessed_timestamp == other.last_accessed_timestamp &&
-         favicon == other.favicon;
+         last_accessed_timestamp == other.last_accessed_timestamp;
 }
 
 bool BrowserTabsModel::BrowserTabMetadata::operator!=(

chromeos/components/phonehub/fake_browser_tabs_metadata_fetcher.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 "chromeos/components/phonehub/fake_browser_tabs_metadata_fetcher.h"
+
+namespace chromeos {
+namespace phonehub {
+
+FakeBrowserTabsMetadataFetcher::FakeBrowserTabsMetadataFetcher() = default;
+
+FakeBrowserTabsMetadataFetcher::~FakeBrowserTabsMetadataFetcher() = default;
+
+void FakeBrowserTabsMetadataFetcher::Fetch(
+    const sync_sessions::SyncedSession* session,
+    base::OnceCallback<void(BrowserTabsMetadataResponse)> callback) {
+  callback_ = std::move(callback);
+}
+
+void FakeBrowserTabsMetadataFetcher::RespondToCurrentFetchAttempt(
+    const BrowserTabsMetadataResponse& response) {
+  std::move(callback_).Run(response);
+}
+
+}  // namespace phonehub
+}  // namespace chromeos

chromeos/components/phonehub/fake_browser_tabs_metadata_fetcher.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 CHROMEOS_COMPONENTS_PHONEHUB_FAKE_BROWSER_TABS_METADATA_FETCHER_H_
+#define CHROMEOS_COMPONENTS_PHONEHUB_FAKE_BROWSER_TABS_METADATA_FETCHER_H_
+
+#include "chromeos/components/phonehub/browser_tabs_metadata_fetcher.h"
+
+namespace chromeos {
+namespace phonehub {
+
+class FakeBrowserTabsMetadataFetcher : public BrowserTabsMetadataFetcher {
+ public:
+  FakeBrowserTabsMetadataFetcher();
+  ~FakeBrowserTabsMetadataFetcher() override;
+
+  // BrowserTabsMetadataFetcher:
+  void Fetch(
+      const sync_sessions::SyncedSession* session,
+      base::OnceCallback<void(BrowserTabsMetadataResponse)> callback) override;
+
+  void RespondToCurrentFetchAttempt(
+      const BrowserTabsMetadataResponse& response);
+
+ private:
+  base::OnceCallback<void(BrowserTabsMetadataResponse)> callback_;
+};
+
+}  // namespace phonehub
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_PHONEHUB_FAKE_BROWSER_TABS_METADATA_FETCHER_H_