Separate the NTP app ordering from the app list app ordering

chrome/browser/ui/app_list/extension_app_item.cc

Index: chrome/browser/ui/app_list/extension_app_item.cc
diff --git a/chrome/browser/ui/app_list/extension_app_item.cc b/chrome/browser/ui/app_list/extension_app_item.cc
index 97912f148fd6ac4464f7929c45ba3711ae297106..ecfba902b91f289052032442ca29f3e98509582e 100644
--- a/chrome/browser/ui/app_list/extension_app_item.cc
+++ b/chrome/browser/ui/app_list/extension_app_item.cc
@@ -7,11 +7,11 @@
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/extensions/extension_sorting.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_list/app_context_menu.h"
 #include "chrome/browser/ui/app_list/app_list_controller_delegate.h"
+#include "chrome/browser/ui/app_list/app_list_extension_ordering.h"
 #include "chrome/browser/ui/extensions/extension_enable_flow.h"
 #include "chrome/browser/ui/webui/ntp/app_launcher_handler.h"
 #include "chrome/common/extensions/extension.h"
@@ -55,10 +55,10 @@ class ShortcutOverlayImageSource : public gfx::CanvasImageSource {
   DISALLOW_COPY_AND_ASSIGN(ShortcutOverlayImageSource);
 };
 
-ExtensionSorting* GetExtensionSorting(Profile* profile) {
+AppListExtensionOrdering* GetExtensionOrdering(Profile* profile) {
   ExtensionService* service =
       extensions::ExtensionSystem::Get(profile)->extension_service();
-  return service->extension_prefs()->extension_sorting();
+  return service->extension_prefs()->app_list_extension_ordering();
 }
 
 const color_utils::HSL shift = {-1, 0, 0.6};
@@ -81,8 +81,9 @@ ExtensionAppItem::ExtensionAppItem(Profile* profile,
                                                           shift)),
       is_platform_app_(is_platform_app) {
   Reload();
-  GetExtensionSorting(profile_)->EnsureValidOrdinals(extension_id_,
-                                                     syncer::StringOrdinal());
+  AppListExtensionOrdering* ordering = GetExtensionOrdering(profile_);
+  if (!ordering->Contains(extension_id_))
+    ordering->InsertAtNextAvailable(extension_id_);
 }
 
 ExtensionAppItem::~ExtensionAppItem() {
@@ -96,6 +97,11 @@ bool ExtensionAppItem::HasOverlay() const {
 #endif
 }
 
+bool ExtensionAppItem::Precedes(const ExtensionAppItem* item) const {
+  return GetExtensionOrdering(profile_)->ExtensionPrecedes(
+      extension_id(), item->extension_id());
+}
+
 void ExtensionAppItem::Reload() {
   const Extension* extension = GetExtension();
   bool is_installing = !extension;
@@ -110,14 +116,6 @@ void ExtensionAppItem::Reload() {
   LoadImage(extension);
 }
 
-syncer::StringOrdinal ExtensionAppItem::GetPageOrdinal() const {
-  return GetExtensionSorting(profile_)->GetPageOrdinal(extension_id_);
-}
-
-syncer::StringOrdinal ExtensionAppItem::GetAppLaunchOrdinal() const {
-  return GetExtensionSorting(profile_)->GetAppLaunchOrdinal(extension_id_);
-}
-
 void ExtensionAppItem::Move(const ExtensionAppItem* prev,
                             const ExtensionAppItem* next) {
   // Does nothing if no predecessor nor successor.
@@ -127,36 +125,13 @@ void ExtensionAppItem::Move(const ExtensionAppItem* prev,
   ExtensionService* service =
       extensions::ExtensionSystem::Get(profile_)->extension_service();
   service->extension_prefs()->SetAppDraggedByUser(extension_id_);
+  AppListExtensionOrdering* ordering = GetExtensionOrdering(profile_);
 
   // Handles only predecessor or only successor case.
-  if (!prev || !next) {
-    syncer::StringOrdinal page = prev ? prev->GetPageOrdinal() :
-                                        next->GetPageOrdinal();
-    GetExtensionSorting(profile_)->SetPageOrdinal(extension_id_, page);
-    service->OnExtensionMoved(extension_id_,
-                              prev ? prev->extension_id() : std::string(),
-                              next ? next->extension_id() : std::string());
-    return;
-  }
-
-  // Handles both predecessor and successor are on the same page.
-  syncer::StringOrdinal prev_page = prev->GetPageOrdinal();
-  syncer::StringOrdinal next_page = next->GetPageOrdinal();
-  if (prev_page.Equals(next_page)) {
-    GetExtensionSorting(profile_)->SetPageOrdinal(extension_id_, prev_page);
-    service->OnExtensionMoved(extension_id_,
-                              prev->extension_id(),
-                              next->extension_id());
-    return;
-  }
-
-  // Otherwise, go with |next|. This is okay because app list does not split
-  // page based ntp page ordinal.
-  // TODO(xiyuan): Revisit this when implementing paging support.
-  GetExtensionSorting(profile_)->SetPageOrdinal(extension_id_, prev_page);
-  service->OnExtensionMoved(extension_id_,
-                            prev->extension_id(),
-                            std::string());
+  GetExtensionOrdering(profile_)->OnExtensionMoved(
+      extension_id_,
+      prev ? prev->extension_id() : std::string(),
+      next ? next->extension_id() : std::string());
 }
 
 void ExtensionAppItem::UpdateIcon() {