Introduce //components/user_prefs.

The user_prefs component provides:

a) The UserPrefs class, used to map PrefService objects to BrowserContext. This addresses a TODO to get rid of PrefServiceFromBrowserContext from base/prefs/pref_service.h, where clearly a mention of a content class did not belong.

b) A place for PrefRegistrySyncable to live, where it can be used by components that need to register prefs.

We also use (b) in this change to eliminate Autofill's dependency on chrome/browser/prefs. Work is ongoing to move Autofill to //components/autofill.

TBR=ben@chromium.org
BUG=155525,140037


Review URL: https://chromiumcodereview.appspot.com/12340111

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@186301 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 477 insertions, 0 deletions

diff --git a/components/user_prefs/DEPS b/components/user_prefs/DEPS
new file mode 100644
index 0000000..c36190b
--- /dev/null
+++ b/components/user_prefs/DEPS
@@ -0,0 +1,4 @@
+include_rules = [
+  "+content/public/browser",
+  "+ui/base",
+]
diff --git a/components/user_prefs/OWNERS b/components/user_prefs/OWNERS
new file mode 100644
index 0000000..024da1c
--- /dev/null
+++ b/components/user_prefs/OWNERS
@@ -0,0 +1,4 @@
+battre@chromium.org
+bauerb@chromium.org
+mnissler@chromium.org
+pam@chromium.org
diff --git a/components/user_prefs/README b/components/user_prefs/README
new file mode 100644
index 0000000..a7ca509
--- /dev/null
+++ b/components/user_prefs/README
@@ -0,0 +1,8 @@
+The //components/user_pref component provides:
+
+a) The UserPrefs class, where components dependent on looking up
+preferences associated with users can look them up by
+content::BrowserContext.
+
+b) A place for PrefRegistrySyncable to live, where it can be used by
+components that need to register preferences associated with users.
diff --git a/components/user_prefs/pref_registry_syncable.cc b/components/user_prefs/pref_registry_syncable.cc
new file mode 100644
index 0000000..874f8a6
--- /dev/null
+++ b/components/user_prefs/pref_registry_syncable.cc
@@ -0,0 +1,220 @@
+// Copyright (c) 2012 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 "components/user_prefs/pref_registry_syncable.h"
+
+#include "base/files/file_path.h"
+#include "base/prefs/default_pref_store.h"
+#include "base/string_number_conversions.h"
+#include "base/values.h"
+#include "ui/base/l10n/l10n_util.h"
+
+namespace {
+
+// A helper function for RegisterLocalized*Pref that creates a Value*
+// based on a localized resource.  Because we control the values in a
+// locale dll, this should always return a Value of the appropriate
+// type.
+base::Value* CreateLocaleDefaultValue(base::Value::Type type,
+                                      int message_id) {
+  const std::string resource_string = l10n_util::GetStringUTF8(message_id);
+  DCHECK(!resource_string.empty());
+  switch (type) {
+    case Value::TYPE_BOOLEAN: {
+      if ("true" == resource_string)
+        return Value::CreateBooleanValue(true);
+      if ("false" == resource_string)
+        return Value::CreateBooleanValue(false);
+      break;
+    }
+
+    case Value::TYPE_INTEGER: {
+      int val;
+      base::StringToInt(resource_string, &val);
+      return Value::CreateIntegerValue(val);
+    }
+
+    case Value::TYPE_DOUBLE: {
+      double val;
+      base::StringToDouble(resource_string, &val);
+      return Value::CreateDoubleValue(val);
+    }
+
+    case Value::TYPE_STRING: {
+      return Value::CreateStringValue(resource_string);
+    }
+
+    default: {
+      NOTREACHED() <<
+          "list and dictionary types cannot have default locale values";
+    }
+  }
+  NOTREACHED();
+  return Value::CreateNullValue();
+}
+
+}  // namespace
+
+PrefRegistrySyncable::PrefRegistrySyncable() {
+}
+
+PrefRegistrySyncable::~PrefRegistrySyncable() {
+}
+
+const std::set<std::string>&
+PrefRegistrySyncable::syncable_preferences() const {
+  return syncable_preferences_;
+}
+
+void PrefRegistrySyncable::SetSyncableRegistrationCallback(
+    const SyncableRegistrationCallback& cb) {
+  callback_ = cb;
+}
+
+void PrefRegistrySyncable::RegisterBooleanPref(const char* path,
+                                               bool default_value,
+                                               PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path,
+                             Value::CreateBooleanValue(default_value),
+                             sync_status);
+}
+
+void PrefRegistrySyncable::RegisterIntegerPref(const char* path,
+                                               int default_value,
+                                               PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path,
+                             Value::CreateIntegerValue(default_value),
+                             sync_status);
+}
+
+void PrefRegistrySyncable::RegisterDoublePref(const char* path,
+                                              double default_value,
+                                              PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path,
+                             Value::CreateDoubleValue(default_value),
+                             sync_status);
+}
+
+void PrefRegistrySyncable::RegisterStringPref(const char* path,
+                                              const std::string& default_value,
+                                              PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path,
+                             Value::CreateStringValue(default_value),
+                             sync_status);
+}
+
+void PrefRegistrySyncable::RegisterFilePathPref(
+    const char* path,
+    const base::FilePath& default_value,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path,
+                             Value::CreateStringValue(default_value.value()),
+                             sync_status);
+}
+
+void PrefRegistrySyncable::RegisterListPref(const char* path,
+                                            PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path, new ListValue(), sync_status);
+}
+
+void PrefRegistrySyncable::RegisterListPref(const char* path,
+                                            ListValue* default_value,
+                                            PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path, default_value, sync_status);
+}
+
+void PrefRegistrySyncable::RegisterDictionaryPref(const char* path,
+                                                  PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path, new DictionaryValue(), sync_status);
+}
+
+void PrefRegistrySyncable::RegisterDictionaryPref(
+    const char* path,
+    DictionaryValue* default_value,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(path, default_value, sync_status);
+}
+
+void PrefRegistrySyncable::RegisterLocalizedBooleanPref(
+    const char* path,
+    int locale_default_message_id,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(
+      path,
+      CreateLocaleDefaultValue(Value::TYPE_BOOLEAN, locale_default_message_id),
+      sync_status);
+}
+
+void PrefRegistrySyncable::RegisterLocalizedIntegerPref(
+    const char* path,
+    int locale_default_message_id,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(
+      path,
+      CreateLocaleDefaultValue(Value::TYPE_INTEGER, locale_default_message_id),
+      sync_status);
+}
+
+void PrefRegistrySyncable::RegisterLocalizedDoublePref(
+    const char* path,
+    int locale_default_message_id,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(
+      path,
+      CreateLocaleDefaultValue(Value::TYPE_DOUBLE, locale_default_message_id),
+      sync_status);
+}
+
+void PrefRegistrySyncable::RegisterLocalizedStringPref(
+    const char* path,
+    int locale_default_message_id,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(
+      path,
+      CreateLocaleDefaultValue(Value::TYPE_STRING, locale_default_message_id),
+      sync_status);
+}
+
+void PrefRegistrySyncable::RegisterInt64Pref(
+    const char* path,
+    int64 default_value,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(
+      path,
+      Value::CreateStringValue(base::Int64ToString(default_value)),
+      sync_status);
+}
+
+void PrefRegistrySyncable::RegisterUint64Pref(
+    const char* path,
+    uint64 default_value,
+    PrefSyncStatus sync_status) {
+  RegisterSyncablePreference(
+      path,
+      Value::CreateStringValue(base::Uint64ToString(default_value)),
+      sync_status);
+}
+
+void PrefRegistrySyncable::RegisterSyncablePreference(
+    const char* path,
+    base::Value* default_value,
+    PrefSyncStatus sync_status) {
+  PrefRegistry::RegisterPreference(path, default_value);
+
+  if (sync_status == SYNCABLE_PREF) {
+    syncable_preferences_.insert(path);
+
+    if (!callback_.is_null())
+      callback_.Run(path);
+  }
+}
+
+scoped_refptr<PrefRegistrySyncable> PrefRegistrySyncable::ForkForIncognito() {
+  // TODO(joi): We can directly reuse the same PrefRegistry once
+  // PrefService no longer registers for callbacks on registration and
+  // unregistration.
+  scoped_refptr<PrefRegistrySyncable> registry(new PrefRegistrySyncable());
+  registry->defaults_ = defaults_;
+  return registry;
+}
diff --git a/components/user_prefs/pref_registry_syncable.h b/components/user_prefs/pref_registry_syncable.h
new file mode 100644
index 0000000..08477f2
--- /dev/null
+++ b/components/user_prefs/pref_registry_syncable.h
@@ -0,0 +1,119 @@
+// Copyright (c) 2012 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 COMPONENTS_USER_PREFS_PREF_REGISTRY_SYNCABLE_H_
+#define COMPONENTS_USER_PREFS_PREF_REGISTRY_SYNCABLE_H_
+
+#include <set>
+#include <string>
+
+#include "base/prefs/pref_registry.h"
+#include "components/user_prefs/user_prefs_export.h"
+
+namespace base {
+class DictionaryValue;
+class FilePath;
+class ListValue;
+class Value;
+}
+
+// A PrefRegistry that forces users to choose whether each registered
+// preference is syncable or not.
+//
+// Classes or components that want to register such preferences should
+// define a static function named RegisterUserPrefs that takes a
+// PrefRegistrySyncable*, and the top-level application using the
+// class or embedding the component should call this function at an
+// appropriate time before the PrefService for these preferences is
+// constructed. See e.g. chrome/browser/prefs/browser_prefs.cc which
+// does this for Chrome.
+class USER_PREFS_EXPORT PrefRegistrySyncable : public PrefRegistry {
+ public:
+  typedef base::Callback<void(const char* path)> SyncableRegistrationCallback;
+
+  // Enum used when registering preferences to determine if it should
+  // be synced or not.
+  enum PrefSyncStatus {
+    UNSYNCABLE_PREF,
+    SYNCABLE_PREF
+  };
+
+  PrefRegistrySyncable();
+
+  // Retrieve the set of syncable preferences currently registered.
+  const std::set<std::string>& syncable_preferences() const;
+
+  // Exactly one callback can be set for the event of a syncable
+  // preference being registered. It will be fired after the
+  // registration has occurred.
+  //
+  // Calling this method after a callback has already been set will
+  // make the object forget the previous callback and use the new one
+  // instead.
+  void SetSyncableRegistrationCallback(const SyncableRegistrationCallback& cb);
+
+  void RegisterBooleanPref(const char* path,
+                           bool default_value,
+                           PrefSyncStatus sync_status);
+  void RegisterIntegerPref(const char* path,
+                           int default_value,
+                           PrefSyncStatus sync_status);
+  void RegisterDoublePref(const char* path,
+                          double default_value,
+                          PrefSyncStatus sync_status);
+  void RegisterStringPref(const char* path,
+                          const std::string& default_value,
+                          PrefSyncStatus sync_status);
+  void RegisterFilePathPref(const char* path,
+                            const base::FilePath& default_value,
+                            PrefSyncStatus sync_status);
+  void RegisterListPref(const char* path,
+                        PrefSyncStatus sync_status);
+  void RegisterDictionaryPref(const char* path,
+                              PrefSyncStatus sync_status);
+  void RegisterListPref(const char* path,
+                        base::ListValue* default_value,
+                        PrefSyncStatus sync_status);
+  void RegisterDictionaryPref(const char* path,
+                              base::DictionaryValue* default_value,
+                              PrefSyncStatus sync_status);
+  void RegisterLocalizedBooleanPref(const char* path,
+                                    int locale_default_message_id,
+                                    PrefSyncStatus sync_status);
+  void RegisterLocalizedIntegerPref(const char* path,
+                                    int locale_default_message_id,
+                                    PrefSyncStatus sync_status);
+  void RegisterLocalizedDoublePref(const char* path,
+                                   int locale_default_message_id,
+                                   PrefSyncStatus sync_status);
+  void RegisterLocalizedStringPref(const char* path,
+                                   int locale_default_message_id,
+                                   PrefSyncStatus sync_status);
+  void RegisterInt64Pref(const char* path,
+                         int64 default_value,
+                         PrefSyncStatus sync_status);
+  void RegisterUint64Pref(const char* path,
+                          uint64 default_value,
+                          PrefSyncStatus sync_status);
+
+  // Returns a new PrefRegistrySyncable that uses the same defaults
+  // store.
+  scoped_refptr<PrefRegistrySyncable> ForkForIncognito();
+
+ private:
+  virtual ~PrefRegistrySyncable();
+
+  void RegisterSyncablePreference(const char* path,
+                                  base::Value* default_value,
+                                  PrefSyncStatus sync_status);
+
+  SyncableRegistrationCallback callback_;
+
+  // Contains the names of all registered preferences that are syncable.
+  std::set<std::string> syncable_preferences_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrefRegistrySyncable);
+};
+
+#endif  // COMPONENTS_USER_PREFS_PREF_REGISTRY_SYNCABLE_H_
diff --git a/components/user_prefs/user_prefs.cc b/components/user_prefs/user_prefs.cc
new file mode 100644
index 0000000..0c920f0
--- /dev/null
+++ b/components/user_prefs/user_prefs.cc
@@ -0,0 +1,44 @@
+// Copyright 2013 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 "components/user_prefs/user_prefs.h"
+
+#include "base/logging.h"
+#include "base/memory/singleton.h"
+#include "base/prefs/pref_service.h"
+#include "content/public/browser/browser_context.h"
+
+namespace components {
+
+namespace {
+
+void* UserDataKey() {
+  // We just need a unique constant. Use the address of this static member.
+  return reinterpret_cast<void*>(&UserPrefs::Get);
+}
+
+}  // namespace
+
+UserPrefs::UserPrefs(PrefService* prefs) : prefs_(prefs) {
+}
+
+UserPrefs::~UserPrefs() {
+}
+
+// static
+PrefService* UserPrefs::Get(content::BrowserContext* context) {
+  DCHECK(context);
+  return static_cast<UserPrefs*>(
+      context->GetUserData(UserDataKey()))->prefs_;
+}
+
+// static
+void UserPrefs::Set(content::BrowserContext* context, PrefService* prefs) {
+  DCHECK(context);
+  DCHECK(prefs);
+  DCHECK(!context->GetUserData(UserDataKey()));
+  context->SetUserData(UserDataKey(), new UserPrefs(prefs));
+}
+
+}  // namespace components
diff --git a/components/user_prefs/user_prefs.h b/components/user_prefs/user_prefs.h
new file mode 100644
index 0000000..1919748
--- /dev/null
+++ b/components/user_prefs/user_prefs.h
@@ -0,0 +1,49 @@
+// Copyright 2013 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 COMPONENTS_USER_PREFS_USER_PREFS_H_
+#define COMPONENTS_USER_PREFS_USER_PREFS_H_
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/supports_user_data.h"
+#include "components/user_prefs/user_prefs_export.h"
+
+class PrefService;
+
+namespace content {
+class BrowserContext;
+}
+
+namespace components {
+
+// Components may use preferences associated with a given user. These
+// hang off of content::BrowserContext and can be retrieved using
+// UserPrefs::Get().
+//
+// It is up to the embedder tof create and own the PrefService and
+// attach it to BrowserContext using the UserPrefs::Set() function.
+class USER_PREFS_EXPORT UserPrefs : public base::SupportsUserData::Data {
+ public:
+  // Retrieves the PrefService for a given BrowserContext, or NULL if
+  // none is attached.
+  static PrefService* Get(content::BrowserContext* context);
+
+  // Hangs the specified |prefs| off of |context|. Should be called
+  // only once per BrowserContext.
+  static void Set(content::BrowserContext* context, PrefService* prefs);
+
+ private:
+  UserPrefs(PrefService* prefs);
+  virtual ~UserPrefs();
+
+  // Non-owning; owned by embedder.
+  PrefService* prefs_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserPrefs);
+};
+
+}  // namespace components
+
+#endif  // COMPONENTS_USER_PREFS_USER_PREFS_H_
diff --git a/components/user_prefs/user_prefs_export.h b/components/user_prefs/user_prefs_export.h
new file mode 100644
index 0000000..3d20222
--- /dev/null
+++ b/components/user_prefs/user_prefs_export.h
@@ -0,0 +1,29 @@
+// Copyright 2013 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 COMPONENTS_USER_PREFS_USER_PREFS_EXPORT_H_
+#define COMPONENTS_USER_PREFS_USER_PREFS_EXPORT_H_
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(USER_PREFS_IMPLEMENTATION)
+#define USER_PREFS_EXPORT __declspec(dllexport)
+#else
+#define USER_PREFS_EXPORT __declspec(dllimport)
+#endif  // defined(BASE_PREFS_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(USER_PREFS_IMPLEMENTATION)
+#define USER_PREFS_EXPORT __attribute__((visibility("default")))
+#else
+#define USER_PREFS_EXPORT
+#endif
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define USER_PREFS_EXPORT
+#endif
+
+#endif  // COMPONENTS_USER_PREFS_USER_PREFS_EXPORT_H_