Delay forcing natural scroll setting until after initial sync.

chrome/browser/chromeos/preferences.cc

 // 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 "chrome/browser/chromeos/preferences.h"
 
 #include "base/chromeos/chromeos_version.h"
 #include "base/command_line.h"
 #include "base/i18n/time_formatting.h"
 #include "base/metrics/histogram.h"
@@ skipping 30 matching lines @@
 
 Preferences::Preferences()
     : prefs_(NULL),
       input_method_manager_(input_method::GetInputMethodManager()) {
 }
 
 Preferences::Preferences(input_method::InputMethodManager* input_method_manager)
     : input_method_manager_(input_method_manager) {
 }
 
-Preferences::~Preferences() {}
+Preferences::~Preferences() {
+  prefs_->RemoveObserver(this);
+}
 
 // static
 void Preferences::RegisterUserPrefs(PrefService* prefs) {
   std::string hardware_keyboard_id;
   // TODO(yusukes): Remove the runtime hack.
   if (base::chromeos::IsRunningOnChromeOS()) {
     input_method::InputMethodManager* manager =
         input_method::GetInputMethodManager();
     if (manager) {
       hardware_keyboard_id =
@@ skipping 318 matching lines @@
       prefs::kLanguageXkbAutoRepeatInterval, prefs, callback);
 
   enable_screen_lock_.Init(prefs::kEnableScreenLock, prefs, callback);
 
   enable_drm_.Init(prefs::kEnableCrosDRM, prefs, callback);
 }
 
 void Preferences::Init(PrefService* prefs) {
   InitUserPrefs(prefs);
 
+  // This causes OnIsSyncingChanged to be called when the value of

[sky, 2012/12/20 16:29:17]

OnIsSyncingChanged()

+  // PrefService::IsSyncing() changes.
+  prefs->AddObserver(this);
+
   // Initialize preferences to currently saved state.
   NotifyPrefChanged(NULL);
 
   // If a guest is logged in, initialize the prefs as if this is the first
   // login.
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kGuestSession)) {
     LoginUtils::Get()->SetFirstLoginPrefs(prefs);
   }
 }
 
@@ skipping 43 matching lines @@
   }
   if (!pref_name || *pref_name == prefs::kEnableTouchpadThreeFingerSwipe) {
     const bool enabled = three_finger_swipe_enabled_.GetValue();
     system::touchpad_settings::SetThreeFingerSwipe(enabled);
     if (pref_name)
       UMA_HISTOGRAM_BOOLEAN("Touchpad.ThreeFingerSwipe.Changed", enabled);
     else
       UMA_HISTOGRAM_BOOLEAN("Touchpad.ThreeFingerSwipe.Started", enabled);
   }
   if (!pref_name || *pref_name == prefs::kNaturalScroll) {
-    // Force natural scroll to on if kNaturalScrollDefault is specified on the
-    // cmd line.
-    if (CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kNaturalScrollDefault) &&
-        !pref_name &&
-        !prefs_->GetUserPrefValue(prefs::kNaturalScroll)) {
-      natural_scroll_.SetValue(true);
-      DVLOG(1) << "Natural scroll forced to true";
-      UMA_HISTOGRAM_BOOLEAN("Touchpad.NaturalScroll.Forced", true);
-    }
+    // Force natural scroll default if we've sync'd and if the cmd line arg is
+    // set.
+    ForceNaturalScrollDefault();

[sky, 2012/12/20 16:29:17]

If you invoke ForceNaturalScrollDefault() here and IsSyncing is false won't you
ignore updating natural_scroll_ even though the user just changed the pref?

[xiyuan, 2012/12/20 17:07:49]

ForceNaturalScrollDefault just attempts to provide a default value based on
command line switch. The pref value handling is @463-469 below.

 
     const bool enabled = natural_scroll_.GetValue();
     DVLOG(1) << "Natural scroll set to " << enabled;
     ui::SetNaturalScroll(enabled);
     if (pref_name)
       UMA_HISTOGRAM_BOOLEAN("Touchpad.NaturalScroll.Changed", enabled);
     else
       UMA_HISTOGRAM_BOOLEAN("Touchpad.NaturalScroll.Started", enabled);
   }
   if (!pref_name || *pref_name == prefs::kMouseSensitivity) {
@@ skipping 197 matching lines @@
     if (disable_drive_.GetValue()) {
       if (drive::util::IsUnderDriveMountPoint(
           download_default_directory_.GetValue())) {
         prefs_->SetFilePath(prefs::kDownloadDefaultDirectory,
                             download_util::GetDefaultDownloadDirectory());
       }
     }
   }
 }
 
+void Preferences::OnIsSyncingChanged() {
+  DVLOG(1) << "OnIsSyncingChanged";
+  ForceNaturalScrollDefault();
+}
+
+void Preferences::ForceNaturalScrollDefault() {
+  DVLOG(1) << "ForceNaturalScrollDefault";
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kNaturalScrollDefault) &&
+      prefs_->IsSyncing() &&
+      !prefs_->GetUserPrefValue(prefs::kNaturalScroll)) {
+    DVLOG(1) << "Natural scroll forced to true";
+    natural_scroll_.SetValue(true);
+    UMA_HISTOGRAM_BOOLEAN("Touchpad.NaturalScroll.Forced", true);
+  }
+}
+
 void Preferences::SetLanguageConfigBoolean(const char* section,
                                            const char* name,
                                            bool value) {
   input_method::InputMethodConfigValue config;
   config.type = input_method::InputMethodConfigValue::kValueTypeBool;
   config.bool_value = value;
   input_method_manager_->SetInputMethodConfig(section, name, config);
 }
 
 void Preferences::SetLanguageConfigInteger(const char* section,
@@ skipping 78 matching lines @@
 
   input_method::AutoRepeatRate rate;
   rate.initial_delay_in_ms = xkb_auto_repeat_delay_pref_.GetValue();
   rate.repeat_interval_in_ms = xkb_auto_repeat_interval_pref_.GetValue();
   DCHECK(rate.initial_delay_in_ms > 0);
   DCHECK(rate.repeat_interval_in_ms > 0);
   input_method::XKeyboard::SetAutoRepeatRate(rate);
 }
 
 }  // namespace chromeos