Reading list model API.

An API for a model to support reading lists plus an in-memory implementation for development purpose. Users of this API should only use the factory to get access to a model.

BUG=None

Review URL: https://codereview.chromium.org/1643573007

Cr-Commit-Position: refs/heads/master@{#375427}

16 files changed, 649 insertions, 0 deletions

diff --git a/ios/chrome/BUILD.gn b/ios/chrome/BUILD.gn
index 59a9731..f59a480 100644
--- a/ios/chrome/BUILD.gn
+++ b/ios/chrome/BUILD.gn
@@ -23,6 +23,8 @@ test("ios_chrome_unittests") {
     "browser/net/image_fetcher_unittest.mm",
     "browser/net/metrics_network_client_unittest.mm",
     "browser/net/retryable_url_fetcher_unittest.mm",
+    "browser/reading_list/reading_list_entry_unittest.cc",
+    "browser/reading_list/reading_list_model_unittest.cc",
     "browser/signin/chrome_identity_service_observer_bridge_unittest.mm",
     "browser/signin/gaia_auth_fetcher_ios_unittest.mm",
     "browser/snapshots/lru_cache_unittest.mm",
diff --git a/ios/chrome/browser/BUILD.gn b/ios/chrome/browser/BUILD.gn
index 648375c..8469be4 100644
--- a/ios/chrome/browser/BUILD.gn
+++ b/ios/chrome/browser/BUILD.gn
@@ -292,6 +292,15 @@ source_set("browser") {
     "prefs/pref_observer_bridge.h",
     "prefs/pref_observer_bridge.mm",
     "procedural_block_types.h",
+    "reading_list/reading_list_entry.cc",
+    "reading_list/reading_list_entry.h",
+    "reading_list/reading_list_model.cc",
+    "reading_list/reading_list_model.h",
+    "reading_list/reading_list_model_factory.cc",
+    "reading_list/reading_list_model_factory.h",
+    "reading_list/reading_list_model_memory.cc",
+    "reading_list/reading_list_model_memory.h",
+    "reading_list/reading_list_model_observer.h",
     "search/search_util.cc",
     "search/search_util.h",
     "search_engines/search_engines_util.cc",
diff --git a/ios/chrome/browser/reading_list/OWNERS b/ios/chrome/browser/reading_list/OWNERS
new file mode 100644
index 0000000..bf1620f
--- /dev/null
+++ b/ios/chrome/browser/reading_list/OWNERS
@@ -0,0 +1 @@
+noyau@chromium.org
diff --git a/ios/chrome/browser/reading_list/reading_list_entry.cc b/ios/chrome/browser/reading_list/reading_list_entry.cc
new file mode 100644
index 0000000..15c0dea
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_entry.cc
@@ -0,0 +1,32 @@
+// 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 "ios/chrome/browser/reading_list/reading_list_entry.h"
+
+ReadingListEntry::ReadingListEntry(const GURL& url, const std::string& title)
+    : url_(url), title_(title) {
+  DCHECK(!url.is_empty());
+  DCHECK(url.is_valid());
+}
+ReadingListEntry::ReadingListEntry(const ReadingListEntry& entry)
+    : url_(entry.url()), title_(entry.title()) {}
+ReadingListEntry::~ReadingListEntry() {}
+
+const GURL& ReadingListEntry::url() const {
+  return url_;
+}
+
+const std::string ReadingListEntry::title() const {
+  return title_;
+}
+
+ReadingListEntry& ReadingListEntry::operator=(const ReadingListEntry& other) {
+  url_ = other.url_;
+  title_ = other.title_;
+  return *this;
+}
+
+bool ReadingListEntry::operator==(const ReadingListEntry& other) const {
+  return url_ == other.url_;
+}
diff --git a/ios/chrome/browser/reading_list/reading_list_entry.h b/ios/chrome/browser/reading_list/reading_list_entry.h
new file mode 100644
index 0000000..f7287b7
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_entry.h
@@ -0,0 +1,32 @@
+// 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.
+
+#ifndef IOS_CHROME_BROWSER_READING_LIST_READING_LIST_ENTRY_H_
+#define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_ENTRY_H_
+
+#include <string>
+
+#include "url/gurl.h"
+
+// An entry in the reading list. The URL is a unique identifier for an entry, as
+// such it should not be empty and is the only thing considered when comparing
+// entries.
+class ReadingListEntry {
+ public:
+  ReadingListEntry(const GURL& url, const std::string& title);
+  ReadingListEntry(const ReadingListEntry& entry);
+  ~ReadingListEntry();
+
+  const GURL& url() const;
+  const std::string title() const;
+
+  ReadingListEntry& operator=(const ReadingListEntry& other);
+  bool operator==(const ReadingListEntry& other) const;
+
+ private:
+  GURL url_;
+  std::string title_;
+};
+
+#endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_ENTRY_H_
diff --git a/ios/chrome/browser/reading_list/reading_list_entry_unittest.cc b/ios/chrome/browser/reading_list/reading_list_entry_unittest.cc
new file mode 100644
index 0000000..1bb920b
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_entry_unittest.cc
@@ -0,0 +1,29 @@
+// 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 "ios/chrome/browser/reading_list/reading_list_entry.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(ReadingListEntry, CompareIgnoreTitle) {
+  const ReadingListEntry e1(GURL("http://example.com"), "bar");
+  const ReadingListEntry e2(GURL("http://example.com"), "foo");
+
+  EXPECT_EQ(e1, e2);
+}
+
+TEST(ReadingListEntry, CompareFailureIgnoreTitle) {
+  const ReadingListEntry e1(GURL("http://example.com"), "bar");
+  const ReadingListEntry e2(GURL("http://example.org"), "bar");
+
+  EXPECT_FALSE(e1 == e2);
+}
+
+TEST(ReadingListEntry, CopyAreEquals) {
+  const ReadingListEntry e1(GURL("http://example.com"), "bar");
+  const ReadingListEntry e2(e1);
+
+  EXPECT_EQ(e1, e2);
+  EXPECT_EQ(e1.title(), e2.title());
+}
diff --git a/ios/chrome/browser/reading_list/reading_list_model.cc b/ios/chrome/browser/reading_list/reading_list_model.cc
new file mode 100644
index 0000000..bdc2651
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model.cc
@@ -0,0 +1,21 @@
+// 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 "ios/chrome/browser/reading_list/reading_list_model.h"
+
+ReadingListModel::ReadingListModel() {}
+ReadingListModel::~ReadingListModel() {}
+
+// Observer methods.
+void ReadingListModel::AddObserver(ReadingListModelObserver* observer) {
+  DCHECK(observer);
+  observers_.AddObserver(observer);
+  if (loaded()) {
+    observer->ReadingListModelLoaded(this);
+  }
+}
+
+void ReadingListModel::RemoveObserver(ReadingListModelObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
diff --git a/ios/chrome/browser/reading_list/reading_list_model.h b/ios/chrome/browser/reading_list/reading_list_model.h
new file mode 100644
index 0000000..196476e
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model.h
@@ -0,0 +1,76 @@
+// 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.
+
+#ifndef IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_H_
+#define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/observer_list.h"
+#include "ios/chrome/browser/reading_list/reading_list_model_observer.h"
+
+class GURL;
+class ReadingListEntry;
+class ReadingListModel;
+
+namespace ios {
+class ChromeBrowserState;
+}
+
+// The reading list model contains two list of entries: one of unread urls, the
+// other of read ones. This object should only be accessed from one thread
+// (Usually the main thread). The observers callbacks are also sent on the main
+// thread.
+class ReadingListModel {
+ public:
+  // Returns true if the model finished loading. Until this returns true the
+  // reading list is not ready for use.
+  virtual bool loaded() const = 0;
+
+  // Returns the size of read and unread entries.
+  virtual size_t unread_size() const = 0;
+  virtual size_t read_size() const = 0;
+
+  // Returns true if there are entries in the model that were not seen by the
+  // user yet. Reset to true when new unread entries are added. Reset to false
+  // when ResetUnseenEntries is called.
+  virtual bool HasUnseenEntries() const = 0;
+  virtual void ResetUnseenEntries() = 0;
+
+  // Returns a specific entry.
+  virtual const ReadingListEntry& GetUnreadEntryAtIndex(size_t index) const = 0;
+  virtual const ReadingListEntry& GetReadEntryAtIndex(size_t index) const = 0;
+
+  // Adds |url| at the top of the unread entries, and removes entries with the
+  // same |url| from everywhere else if they exist. The addition may be
+  // asynchronous, and the data will be available only once the observers are
+  // notified.
+  virtual const ReadingListEntry& AddEntry(const GURL& url,
+                                           const std::string& title) = 0;
+
+  // Removes an entry. The removal may be asynchronous, and not happen
+  // immediately.
+  virtual void RemoveEntryByUrl(const GURL& url) = 0;
+
+  // If the |url| is in the reading list and unread, mark it read. If it is in
+  // the reading list and read, move it to the top of unread if it is not here
+  // already. This may trigger deletion of old read entries.
+  virtual void MarkReadByURL(const GURL& url) = 0;
+
+  // Observer registration methods.
+  void AddObserver(ReadingListModelObserver* observer);
+  void RemoveObserver(ReadingListModelObserver* observer);
+
+ protected:
+  ReadingListModel();
+  virtual ~ReadingListModel();
+  // The observers.
+  base::ObserverList<ReadingListModelObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ReadingListModel);
+};
+
+#endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_H_
diff --git a/ios/chrome/browser/reading_list/reading_list_model_factory.cc b/ios/chrome/browser/reading_list/reading_list_model_factory.cc
new file mode 100644
index 0000000..dcf6c2b
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model_factory.cc
@@ -0,0 +1,51 @@
+// 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 "ios/chrome/browser/reading_list/reading_list_model_factory.h"
+
+#include <utility>
+
+#include "base/memory/singleton.h"
+#include "components/keyed_service/ios/browser_state_dependency_manager.h"
+#include "ios/chrome/browser/browser_state/browser_state_otr_helper.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/reading_list/reading_list_model_memory.h"
+
+// static
+ReadingListModel* ReadingListModelFactory::GetForBrowserState(
+    ios::ChromeBrowserState* browser_state) {
+  return static_cast<ReadingListModelMemory*>(
+      GetInstance()->GetServiceForBrowserState(browser_state, true));
+}
+
+// static
+ReadingListModel* ReadingListModelFactory::GetForBrowserStateIfExists(
+    ios::ChromeBrowserState* browser_state) {
+  return static_cast<ReadingListModelMemory*>(
+      GetInstance()->GetServiceForBrowserState(browser_state, false));
+}
+
+// static
+ReadingListModelFactory* ReadingListModelFactory::GetInstance() {
+  return base::Singleton<ReadingListModelFactory>::get();
+}
+
+ReadingListModelFactory::ReadingListModelFactory()
+    : BrowserStateKeyedServiceFactory(
+          "ReadingListModel",
+          BrowserStateDependencyManager::GetInstance()) {}
+
+ReadingListModelFactory::~ReadingListModelFactory() {}
+
+scoped_ptr<KeyedService> ReadingListModelFactory::BuildServiceInstanceFor(
+    web::BrowserState* context) const {
+  scoped_ptr<ReadingListModelMemory> reading_list_model(
+      new ReadingListModelMemory());
+  return std::move(reading_list_model);
+}
+
+web::BrowserState* ReadingListModelFactory::GetBrowserStateToUse(
+    web::BrowserState* context) const {
+  return GetBrowserStateRedirectedInIncognito(context);
+}
diff --git a/ios/chrome/browser/reading_list/reading_list_model_factory.h b/ios/chrome/browser/reading_list/reading_list_model_factory.h
new file mode 100644
index 0000000..96a6638
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model_factory.h
@@ -0,0 +1,46 @@
+// 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.
+
+#ifndef IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_FACTORY_H_
+#define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_FACTORY_H_
+
+#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
+
+namespace base {
+template <typename T>
+struct DefaultSingletonTraits;
+}  // namespace base
+
+class ReadingListModel;
+
+namespace ios {
+class ChromeBrowserState;
+}
+
+// Singleton that owns the ReadingListModel and associates it with
+// ios::ChromeBrowserState.
+class ReadingListModelFactory : public BrowserStateKeyedServiceFactory {
+ public:
+  static ReadingListModel* GetForBrowserState(
+      ios::ChromeBrowserState* browser_state);
+  static ReadingListModel* GetForBrowserStateIfExists(
+      ios::ChromeBrowserState* browser_state);
+  static ReadingListModelFactory* GetInstance();
+
+ private:
+  friend struct base::DefaultSingletonTraits<ReadingListModelFactory>;
+
+  ReadingListModelFactory();
+  ~ReadingListModelFactory() override;
+
+  // BrowserStateKeyedServiceFactory implementation.
+  scoped_ptr<KeyedService> BuildServiceInstanceFor(
+      web::BrowserState* context) const override;
+  web::BrowserState* GetBrowserStateToUse(
+      web::BrowserState* context) const override;
+
+  DISALLOW_COPY_AND_ASSIGN(ReadingListModelFactory);
+};
+
+#endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_FACTORY_H_
diff --git a/ios/chrome/browser/reading_list/reading_list_model_memory.cc b/ios/chrome/browser/reading_list/reading_list_model_memory.cc
new file mode 100644
index 0000000..40f9224
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model_memory.cc
@@ -0,0 +1,117 @@
+// 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 "ios/chrome/browser/reading_list/reading_list_model_memory.h"
+
+#include "url/gurl.h"
+
+ReadingListModelMemory::ReadingListModelMemory()
+    : hasUnseen_(false), loaded_(true) {}
+ReadingListModelMemory::~ReadingListModelMemory() {}
+
+void ReadingListModelMemory::Shutdown() {
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListModelBeingDeleted(this));
+  loaded_ = false;
+}
+
+bool ReadingListModelMemory::loaded() const {
+  return loaded_;
+}
+
+size_t ReadingListModelMemory::unread_size() const {
+  DCHECK(loaded());
+  return unread_.size();
+}
+
+size_t ReadingListModelMemory::read_size() const {
+  DCHECK(loaded());
+  return read_.size();
+}
+
+bool ReadingListModelMemory::HasUnseenEntries() const {
+  DCHECK(loaded());
+  return unread_size() && hasUnseen_;
+}
+
+void ReadingListModelMemory::ResetUnseenEntries() {
+  DCHECK(loaded());
+  hasUnseen_ = false;
+}
+
+// Returns a specific entry.
+const ReadingListEntry& ReadingListModelMemory::GetUnreadEntryAtIndex(
+    size_t index) const {
+  DCHECK(loaded());
+  return unread_[index];
+}
+const ReadingListEntry& ReadingListModelMemory::GetReadEntryAtIndex(
+    size_t index) const {
+  DCHECK(loaded());
+  return read_[index];
+}
+
+void ReadingListModelMemory::RemoveEntryByUrl(const GURL& url) {
+  DCHECK(loaded());
+  const ReadingListEntry entry(url, std::string());
+
+  auto result = std::find(unread_.begin(), unread_.end(), entry);
+  if (result != unread_.end()) {
+    FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                      ReadingListWillRemoveUnreadEntry(
+                          this, std::distance(unread_.begin(), result)));
+    unread_.erase(result);
+    FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                      ReadingListDidApplyChanges(this));
+    return;
+  }
+
+  result = std::find(read_.begin(), read_.end(), entry);
+  if (result != read_.end()) {
+    FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                      ReadingListWillRemoveReadEntry(
+                          this, std::distance(read_.begin(), result)));
+    read_.erase(result);
+    FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                      ReadingListDidApplyChanges(this));
+    return;
+  }
+}
+
+const ReadingListEntry& ReadingListModelMemory::AddEntry(
+    const GURL& url,
+    const std::string& title) {
+  DCHECK(loaded());
+  RemoveEntryByUrl(url);
+  const ReadingListEntry entry(url, title);
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListWillAddUnreadEntry(this, entry));
+  unread_.insert(unread_.begin(), entry);
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListDidApplyChanges(this));
+
+  hasUnseen_ = true;
+  return *unread_.begin();
+}
+
+void ReadingListModelMemory::MarkReadByURL(const GURL& url) {
+  DCHECK(loaded());
+  const ReadingListEntry entry(url, std::string());
+
+  auto result = std::find(unread_.begin(), unread_.end(), entry);
+  if (result == unread_.end()) {
+    return;
+  }
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListWillRemoveUnreadEntry(
+                        this, std::distance(unread_.begin(), result)));
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListWillAddReadEntry(this, entry));
+
+  read_.insert(read_.begin(), *result);
+  unread_.erase(result);
+
+  FOR_EACH_OBSERVER(ReadingListModelObserver, observers_,
+                    ReadingListDidApplyChanges(this));
+}
diff --git a/ios/chrome/browser/reading_list/reading_list_model_memory.h b/ios/chrome/browser/reading_list/reading_list_model_memory.h
new file mode 100644
index 0000000..1dda495
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model_memory.h
@@ -0,0 +1,44 @@
+// 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.
+
+#ifndef IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_MEMORY_H_
+#define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_MEMORY_H_
+
+#include "components/keyed_service/core/keyed_service.h"
+#include "ios/chrome/browser/reading_list/reading_list_entry.h"
+#include "ios/chrome/browser/reading_list/reading_list_model.h"
+
+// Concrete implementation of a reading list model using in memory lists.
+class ReadingListModelMemory : public ReadingListModel, public KeyedService {
+ public:
+  ReadingListModelMemory();
+  ~ReadingListModelMemory() override;
+  void Shutdown() override;
+
+  bool loaded() const override;
+  size_t unread_size() const override;
+  size_t read_size() const override;
+
+  bool HasUnseenEntries() const override;
+  void ResetUnseenEntries() override;
+
+  // Returns a specific entry.
+  const ReadingListEntry& GetUnreadEntryAtIndex(size_t index) const override;
+  const ReadingListEntry& GetReadEntryAtIndex(size_t index) const override;
+
+  void RemoveEntryByUrl(const GURL& url) override;
+
+  const ReadingListEntry& AddEntry(const GURL& url,
+                                   const std::string& title) override;
+
+  void MarkReadByURL(const GURL& url) override;
+
+ private:
+  std::vector<ReadingListEntry> unread_;
+  std::vector<ReadingListEntry> read_;
+  bool hasUnseen_;
+  bool loaded_;
+};
+
+#endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_MEMORY_H_
diff --git a/ios/chrome/browser/reading_list/reading_list_model_observer.h b/ios/chrome/browser/reading_list/reading_list_model_observer.h
new file mode 100644
index 0000000..4881d39
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model_observer.h
@@ -0,0 +1,55 @@
+// 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.
+
+#ifndef IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_OBSERVER_H_
+#define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_OBSERVER_H_
+
+#import <set>
+#import <vector>
+
+class ReadingListModel;
+class ReadingListEntry;
+
+// Observer for the Reading List model. In the observer methods care should be
+// taken to not modify the model.
+class ReadingListModelObserver {
+ public:
+  // Invoked when the model has finished loading. Until this method is called it
+  // is unsafe to use the model.
+  virtual void ReadingListModelLoaded(const ReadingListModel* model) = 0;
+
+  // Invoked from the destructor of the model. The model is no longer valid
+  // after this call.
+  virtual void ReadingListModelBeingDeleted(const ReadingListModel* model) {}
+
+  // Invoked when elements are about to be removed from the read or unread list.
+  virtual void ReadingListWillRemoveUnreadEntry(const ReadingListModel* model,
+                                                size_t index) {}
+  virtual void ReadingListWillRemoveReadEntry(const ReadingListModel* model,
+                                              size_t index) {}
+
+  // Invoked when elements are added to the read or the unread list. The new
+  // entries are always added at the beginning. these methods may be called
+  // multiple time (to process changes coming from a synchronization for
+  // example) and they will be executed in call order, the last call will end up
+  // in first position.
+  virtual void ReadingListWillAddUnreadEntry(const ReadingListModel* model,
+                                             const ReadingListEntry& entry) {}
+
+  virtual void ReadingListWillAddReadEntry(const ReadingListModel* model,
+                                           const ReadingListEntry& entry) {}
+
+  // Called after all th"e changes signaled by calls to the "Will" methods are
+  // done. All the "Will" methods are called as necessary, then the changes
+  // are applied and then this method is called.
+  virtual void ReadingListDidApplyChanges(ReadingListModel* model) {}
+
+ protected:
+  ReadingListModelObserver() {}
+  virtual ~ReadingListModelObserver() {}
+
+  DISALLOW_COPY_AND_ASSIGN(ReadingListModelObserver);
+};
+
+#endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_MODEL_OBSERVER_H_
diff --git a/ios/chrome/browser/reading_list/reading_list_model_unittest.cc b/ios/chrome/browser/reading_list/reading_list_model_unittest.cc
new file mode 100644
index 0000000..a863707
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_model_unittest.cc
@@ -0,0 +1,123 @@
+// 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 "ios/chrome/browser/reading_list/reading_list_model_memory.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class ReadingListModelTest : public ReadingListModelObserver,
+                             public testing::Test {
+ public:
+  ReadingListModelTest() : model_(new ReadingListModelMemory()) {
+    ClearCounts();
+    model_->AddObserver(this);
+  }
+  ~ReadingListModelTest() override {}
+
+  void ClearCounts() {
+    observer_loaded_ = observer_deleted_ = observer_remove_unread_ =
+        observer_remove_read_ = observer_add_unread_ = observer_add_read_ =
+            observer_did_apply_ = 0;
+  }
+
+  void AssertObserverCount(int observer_loaded,
+                           int observer_deleted,
+                           int observer_remove_unread,
+                           int observer_remove_read,
+                           int observer_add_unread,
+                           int observer_add_read,
+                           int observer_did_apply) {
+    ASSERT_EQ(observer_loaded, observer_loaded_);
+    ASSERT_EQ(observer_deleted, observer_deleted_);
+    ASSERT_EQ(observer_remove_unread, observer_remove_unread_);
+    ASSERT_EQ(observer_remove_read, observer_remove_read_);
+    ASSERT_EQ(observer_add_unread, observer_add_unread_);
+    ASSERT_EQ(observer_add_read, observer_add_read_);
+    ASSERT_EQ(observer_did_apply, observer_did_apply_);
+  }
+
+  // ReadingListModelObserver
+  void ReadingListModelLoaded(const ReadingListModel* model) override {
+    observer_loaded_ += 1;
+  }
+  void ReadingListModelBeingDeleted(const ReadingListModel* model) override {
+    observer_deleted_ += 1;
+  }
+  void ReadingListWillRemoveUnreadEntry(const ReadingListModel* model,
+                                        size_t index) override {
+    observer_remove_unread_ += 1;
+  }
+  void ReadingListWillRemoveReadEntry(const ReadingListModel* model,
+                                      size_t index) override {
+    observer_remove_read_ += 1;
+  }
+  void ReadingListWillAddUnreadEntry(const ReadingListModel* model,
+                                     const ReadingListEntry& entry) override {
+    observer_add_unread_ += 1;
+  }
+  void ReadingListWillAddReadEntry(const ReadingListModel* model,
+                                   const ReadingListEntry& entry) override {
+    observer_add_read_ += 1;
+  }
+  void ReadingListDidApplyChanges(ReadingListModel* model) override {
+    observer_did_apply_ += 1;
+  }
+
+ protected:
+  int observer_loaded_;
+  int observer_deleted_;
+  int observer_remove_unread_;
+  int observer_remove_read_;
+  int observer_add_unread_;
+  int observer_add_read_;
+  int observer_did_apply_;
+
+  scoped_ptr<ReadingListModelMemory> model_;
+};
+
+TEST_F(ReadingListModelTest, EmptyLoaded) {
+  EXPECT_TRUE(model_->loaded());
+  AssertObserverCount(1, 0, 0, 0, 0, 0, 0);
+  EXPECT_EQ(0ul, model_->unread_size());
+  EXPECT_EQ(0ul, model_->read_size());
+  model_->Shutdown();
+  EXPECT_FALSE(model_->loaded());
+  AssertObserverCount(1, 1, 0, 0, 0, 0, 0);
+}
+
+TEST_F(ReadingListModelTest, AddEntry) {
+  ClearCounts();
+  const ReadingListEntry entry =
+      model_->AddEntry(GURL("http://example.com"), "sample");
+  EXPECT_EQ(GURL("http://example.com"), entry.url());
+  EXPECT_EQ("sample", entry.title());
+
+  AssertObserverCount(0, 0, 0, 0, 1, 0, 1);
+  EXPECT_EQ(1ul, model_->unread_size());
+  EXPECT_EQ(0ul, model_->read_size());
+  EXPECT_TRUE(model_->HasUnseenEntries());
+
+  const ReadingListEntry other_entry = model_->GetUnreadEntryAtIndex(0);
+  EXPECT_EQ(GURL("http://example.com"), other_entry.url());
+  EXPECT_EQ("sample", other_entry.title());
+}
+
+TEST_F(ReadingListModelTest, ReadEntry) {
+  const ReadingListEntry entry =
+      model_->AddEntry(GURL("http://example.com"), "sample");
+
+  ClearCounts();
+  model_->MarkReadByURL(GURL("http://example.com"));
+  AssertObserverCount(0, 0, 1, 0, 0, 1, 1);
+  EXPECT_EQ(0ul, model_->unread_size());
+  EXPECT_EQ(1ul, model_->read_size());
+  EXPECT_FALSE(model_->HasUnseenEntries());
+
+  const ReadingListEntry other_entry = model_->GetReadEntryAtIndex(0);
+  EXPECT_EQ(GURL("http://example.com"), other_entry.url());
+  EXPECT_EQ("sample", other_entry.title());
+}
+
+}  // namespace
diff --git a/ios/chrome/ios_chrome.gyp b/ios/chrome/ios_chrome.gyp
index a1ac53d..50af6e1 100644
--- a/ios/chrome/ios_chrome.gyp
+++ b/ios/chrome/ios_chrome.gyp
@@ -447,6 +447,15 @@
         'browser/prefs/pref_observer_bridge.h',
         'browser/prefs/pref_observer_bridge.mm',
         'browser/procedural_block_types.h',
+        'browser/reading_list/reading_list_entry.cc',
+        'browser/reading_list/reading_list_entry.h',
+        'browser/reading_list/reading_list_model.cc',
+        'browser/reading_list/reading_list_model.h',
+        'browser/reading_list/reading_list_model_factory.cc',
+        'browser/reading_list/reading_list_model_factory.h',
+        'browser/reading_list/reading_list_model_memory.cc',
+        'browser/reading_list/reading_list_model_memory.h',
+        'browser/reading_list/reading_list_model_observer.h',
         'browser/search/search_util.cc',
         'browser/search/search_util.h',
         'browser/search_engines/search_engines_util.cc',
diff --git a/ios/chrome/ios_chrome_tests.gyp b/ios/chrome/ios_chrome_tests.gyp
index 70012fe..d72f00e 100644
--- a/ios/chrome/ios_chrome_tests.gyp
+++ b/ios/chrome/ios_chrome_tests.gyp
@@ -55,6 +55,8 @@
         'browser/net/image_fetcher_unittest.mm',
         'browser/net/metrics_network_client_unittest.mm',
         'browser/net/retryable_url_fetcher_unittest.mm',
+        'browser/reading_list/reading_list_entry_unittest.cc',
+        'browser/reading_list/reading_list_model_unittest.cc',
         'browser/signin/chrome_identity_service_observer_bridge_unittest.mm',
         'browser/signin/gaia_auth_fetcher_ios_unittest.mm',
         'browser/snapshots/lru_cache_unittest.mm',