--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -665,16 +665,21 @@ pref("plugin.defaultXpi.state", 2);
 pref("plugin.state.flash", 2);
 pref("plugin.state.java", 1);
 
 #ifdef XP_WIN
 pref("browser.preferences.instantApply", false);
 #else
 pref("browser.preferences.instantApply", true);
 #endif
+// Once the Storage Management is completed.
+// (The Storage Management-related prefs are browser.storageManager.* )
+// The Offline(Appcache) Group section in about:preferences will be hidden.
+// And the task to clear appcache will be done by Storage Management.
+pref("browser.preferences.offlineGroup.enabled", true);
 
 pref("browser.download.show_plugins_in_list", true);
 pref("browser.download.hide_plugins_without_extensions", true);
 
 // Backspace and Shift+Backspace behavior
 // 0 goes Back/Forward
 // 1 act like PgUp/PgDown
 // 2 and other values, nothing

--- a/browser/components/preferences/in-content-old/advanced.js
+++ b/browser/components/preferences/in-content-old/advanced.js
@@ -37,28 +37,26 @@ var gAdvancedPane = {
       let onUnload = function() {
         window.removeEventListener("unload", onUnload);
         Services.prefs.removeObserver("app.update.", this);
       }.bind(this);
       window.addEventListener("unload", onUnload);
       Services.prefs.addObserver("app.update.", this, false);
       this.updateReadPrefs();
     }
-    this.updateOfflineApps();
     if (AppConstants.MOZ_CRASHREPORTER) {
       this.initSubmitCrashes();
     }
     this.initTelemetry();
     if (AppConstants.MOZ_TELEMETRY_REPORTING) {
       this.initSubmitHealthReport();
     }
     this.updateOnScreenKeyboardVisibility();
     this.updateCacheSizeInputField();
     this.updateActualCacheSize();
-    this.updateActualAppCacheSize();
 
     if (Services.prefs.getBoolPref("browser.storageManager.enabled")) {
       Services.obs.addObserver(this, "sitedatamanager:sites-updated", false);
       let unload = () => {
         window.removeEventListener("unload", unload);
         Services.obs.removeObserver(this, "sitedatamanager:sites-updated");
       };
       window.addEventListener("unload", unload);
@@ -80,40 +78,47 @@ var gAdvancedPane = {
       setEventListener("submitHealthReportBox", "command",
                        gAdvancedPane.updateSubmitHealthReport);
     }
 
     setEventListener("connectionSettings", "command",
                      gAdvancedPane.showConnections);
     setEventListener("clearCacheButton", "command",
                      gAdvancedPane.clearCache);
-    setEventListener("clearOfflineAppCacheButton", "command",
-                     gAdvancedPane.clearOfflineAppCache);
-    setEventListener("offlineNotifyExceptions", "command",
-                     gAdvancedPane.showOfflineExceptions);
-    setEventListener("offlineAppsList", "select",
-                     gAdvancedPane.offlineAppSelected);
-    let bundlePrefs = document.getElementById("bundlePreferences");
-    document.getElementById("offlineAppsList")
-            .style.height = bundlePrefs.getString("offlineAppsList.height");
-    setEventListener("offlineAppsListRemove", "command",
-                     gAdvancedPane.removeOfflineApp);
     if (AppConstants.MOZ_UPDATER) {
       setEventListener("updateRadioGroup", "command",
                        gAdvancedPane.updateWritePrefs);
       setEventListener("showUpdateHistory", "command",
                        gAdvancedPane.showUpdates);
     }
     setEventListener("viewCertificatesButton", "command",
                      gAdvancedPane.showCertificates);
     setEventListener("viewSecurityDevicesButton", "command",
                      gAdvancedPane.showSecurityDevices);
     setEventListener("cacheSize", "change",
                      gAdvancedPane.updateCacheSizePref);
 
+    if (Services.prefs.getBoolPref("browser.preferences.offlineGroup.enabled")) {
+      this.updateOfflineApps();
+      this.updateActualAppCacheSize();
+      setEventListener("offlineNotifyExceptions", "command",
+                      gAdvancedPane.showOfflineExceptions);
+      setEventListener("offlineAppsList", "select",
+                      gAdvancedPane.offlineAppSelected);
+      setEventListener("offlineAppsListRemove", "command",
+                      gAdvancedPane.removeOfflineApp);
+      setEventListener("clearOfflineAppCacheButton", "command",
+                      gAdvancedPane.clearOfflineAppCache);
+      let bundlePrefs = document.getElementById("bundlePreferences");
+      document.getElementById("offlineAppsList")
+              .style.height = bundlePrefs.getString("offlineAppsList.height");
+      let offlineGroup = document.getElementById("offlineGroup");
+      offlineGroup.hidden = false;
+    }
+
     if (AppConstants.MOZ_WIDGET_GTK) {
       // GTK tabbox' allow the scroll wheel to change the selected tab,
       // but we don't want this behavior for the in-content preferences.
       let tabsElement = document.getElementById("tabsElement");
       tabsElement.addEventListener("DOMMouseScroll", event => {
         event.stopPropagation();
       }, true);
     }
@@ -393,42 +398,16 @@ var gAdvancedPane = {
     try {
       var cacheService =
         Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
                   .getService(Components.interfaces.nsICacheStorageService);
       cacheService.asyncGetDiskConsumption(this.observer);
     } catch (e) {}
   },
 
-  // Retrieves the amount of space currently used by offline cache
-  updateActualAppCacheSize() {
-    var visitor = {
-      onCacheStorageInfo(aEntryCount, aConsumption, aCapacity, aDiskDirectory) {
-        var actualSizeLabel = document.getElementById("actualAppCacheSize");
-        var sizeStrings = DownloadUtils.convertByteUnits(aConsumption);
-        var prefStrBundle = document.getElementById("bundlePreferences");
-        // The XBL binding for the string bundle may have been destroyed if
-        // the page was closed before this callback was executed.
-        if (!prefStrBundle.getFormattedString) {
-          return;
-        }
-        var sizeStr = prefStrBundle.getFormattedString("actualAppCacheSize", sizeStrings);
-        actualSizeLabel.value = sizeStr;
-      }
-    };
-
-    try {
-      var cacheService =
-        Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
-                  .getService(Components.interfaces.nsICacheStorageService);
-      var storage = cacheService.appCacheStorage(LoadContextInfo.default, null);
-      storage.asyncVisitStorage(visitor, false);
-    } catch (e) {}
-  },
-
   updateCacheSizeUI(smartSizeEnabled) {
     document.getElementById("useCacheBefore").disabled = smartSizeEnabled;
     document.getElementById("cacheSize").disabled = smartSizeEnabled;
     document.getElementById("useCacheAfter").disabled = smartSizeEnabled;
   },
 
   readSmartSizeEnabled() {
     // The smart_size.enabled preference element is inverted="true", so its
@@ -470,27 +449,16 @@ var gAdvancedPane = {
     try {
       var cache = Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
                             .getService(Components.interfaces.nsICacheStorageService);
       cache.clear();
     } catch (ex) {}
     this.updateActualCacheSize();
   },
 
-  /**
-   * Clears the application cache.
-   */
-  clearOfflineAppCache() {
-    Components.utils.import("resource:///modules/offlineAppCache.jsm");
-    OfflineAppCacheHelper.clear();
-
-    this.updateActualAppCacheSize();
-    this.updateOfflineApps();
-  },
-
   clearSiteData() {
     let flags =
       Services.prompt.BUTTON_TITLE_IS_STRING * Services.prompt.BUTTON_POS_0 +
       Services.prompt.BUTTON_TITLE_CANCEL * Services.prompt.BUTTON_POS_1 +
       Services.prompt.BUTTON_POS_0_DEFAULT;
     let prefStrBundle = document.getElementById("bundlePreferences");
     let title = prefStrBundle.getString("clearSiteDataPromptTitle");
     let text = prefStrBundle.getString("clearSiteDataPromptText");
@@ -498,16 +466,55 @@ var gAdvancedPane = {
 
     let result = Services.prompt.confirmEx(
       window, title, text, flags, btn0Label, null, null, null, {});
     if (result == 0) {
       SiteDataManager.removeAll();
     }
   },
 
+  // Methods for Offline Apps(Appcache)
+
+  /**
+   * Clears the application cache.
+   */
+  clearOfflineAppCache() {
+    Components.utils.import("resource:///modules/offlineAppCache.jsm");
+    OfflineAppCacheHelper.clear();
+
+    this.updateActualAppCacheSize();
+    this.updateOfflineApps();
+  },
+
+  // Retrieves the amount of space currently used by offline cache
+  updateActualAppCacheSize() {
+    var visitor = {
+      onCacheStorageInfo(aEntryCount, aConsumption, aCapacity, aDiskDirectory) {
+        var actualSizeLabel = document.getElementById("actualAppCacheSize");
+        var sizeStrings = DownloadUtils.convertByteUnits(aConsumption);
+        var prefStrBundle = document.getElementById("bundlePreferences");
+        // The XBL binding for the string bundle may have been destroyed if
+        // the page was closed before this callback was executed.
+        if (!prefStrBundle.getFormattedString) {
+          return;
+        }
+        var sizeStr = prefStrBundle.getFormattedString("actualAppCacheSize", sizeStrings);
+        actualSizeLabel.value = sizeStr;
+      }
+    };
+
+    try {
+      var cacheService =
+        Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
+                  .getService(Components.interfaces.nsICacheStorageService);
+      var storage = cacheService.appCacheStorage(LoadContextInfo.default, null);
+      storage.asyncVisitStorage(visitor, false);
+    } catch (e) {}
+  },
+
   readOfflineNotify() {
     var pref = document.getElementById("browser.offline-apps.notify");
     var button = document.getElementById("offlineNotifyExceptions");
     button.disabled = !pref.value;
     return pref.value;
   },
 
   showOfflineExceptions() {
@@ -641,16 +648,17 @@ var gAdvancedPane = {
       } catch (e) {}
 
       pm.removePermission(perm);
     }
     list.removeChild(item);
     gAdvancedPane.offlineAppSelected();
     this.updateActualAppCacheSize();
   },
+  // Methods for Offline Apps(Appcache) end
 
   // UPDATE TAB
 
   /*
    * Preferences:
    *
    * app.update.enabled
    * - true if updates to the application are enabled, false otherwise

--- a/browser/components/preferences/in-content-old/advanced.xul
+++ b/browser/components/preferences/in-content-old/advanced.xul
@@ -286,17 +286,17 @@
           </label>
           <textbox id="cacheSize" type="number" size="4" max="1024"
                    aria-labelledby="useCacheBefore cacheSize useCacheAfter"/>
           <label id="useCacheAfter" flex="1">&limitCacheSizeAfter.label;</label>
         </hbox>
       </groupbox>
 
       <!-- Offline apps -->
-      <groupbox id="offlineGroup">
+      <groupbox id="offlineGroup" hidden="true">
         <caption><label>&offlineStorage2.label;</label></caption>
 
         <hbox align="center">
           <label id="actualAppCacheSize" flex="1"/>
           <button id="clearOfflineAppCacheButton" icon="clear"
                   label="&clearOfflineAppCacheNow.label;" accesskey="&clearOfflineAppCacheNow.accesskey;"/>
         </hbox>
         <hbox align="center">

--- a/browser/components/preferences/in-content/advanced.js
+++ b/browser/components/preferences/in-content/advanced.js
@@ -37,28 +37,26 @@ var gAdvancedPane = {
       let onUnload = function() {
         window.removeEventListener("unload", onUnload);
         Services.prefs.removeObserver("app.update.", this);
       }.bind(this);
       window.addEventListener("unload", onUnload);
       Services.prefs.addObserver("app.update.", this, false);
       this.updateReadPrefs();
     }
-    this.updateOfflineApps();
     if (AppConstants.MOZ_CRASHREPORTER) {
       this.initSubmitCrashes();
     }
     this.initTelemetry();
     if (AppConstants.MOZ_TELEMETRY_REPORTING) {
       this.initSubmitHealthReport();
     }
     this.updateOnScreenKeyboardVisibility();
     this.updateCacheSizeInputField();
     this.updateActualCacheSize();
-    this.updateActualAppCacheSize();
 
     if (Services.prefs.getBoolPref("browser.storageManager.enabled")) {
       Services.obs.addObserver(this, "sitedatamanager:sites-updated", false);
       let unload = () => {
         window.removeEventListener("unload", unload);
         Services.obs.removeObserver(this, "sitedatamanager:sites-updated");
       };
       window.addEventListener("unload", unload);
@@ -80,40 +78,47 @@ var gAdvancedPane = {
       setEventListener("submitHealthReportBox", "command",
                        gAdvancedPane.updateSubmitHealthReport);
     }
 
     setEventListener("connectionSettings", "command",
                      gAdvancedPane.showConnections);
     setEventListener("clearCacheButton", "command",
                      gAdvancedPane.clearCache);
-    setEventListener("clearOfflineAppCacheButton", "command",
-                     gAdvancedPane.clearOfflineAppCache);
-    setEventListener("offlineNotifyExceptions", "command",
-                     gAdvancedPane.showOfflineExceptions);
-    setEventListener("offlineAppsList", "select",
-                     gAdvancedPane.offlineAppSelected);
-    let bundlePrefs = document.getElementById("bundlePreferences");
-    document.getElementById("offlineAppsList")
-            .style.height = bundlePrefs.getString("offlineAppsList.height");
-    setEventListener("offlineAppsListRemove", "command",
-                     gAdvancedPane.removeOfflineApp);
     if (AppConstants.MOZ_UPDATER) {
       setEventListener("updateRadioGroup", "command",
                        gAdvancedPane.updateWritePrefs);
       setEventListener("showUpdateHistory", "command",
                        gAdvancedPane.showUpdates);
     }
     setEventListener("viewCertificatesButton", "command",
                      gAdvancedPane.showCertificates);
     setEventListener("viewSecurityDevicesButton", "command",
                      gAdvancedPane.showSecurityDevices);
     setEventListener("cacheSize", "change",
                      gAdvancedPane.updateCacheSizePref);
 
+    if (Services.prefs.getBoolPref("browser.preferences.offlineGroup.enabled")) {
+      this.updateOfflineApps();
+      this.updateActualAppCacheSize();
+      setEventListener("offlineNotifyExceptions", "command",
+                      gAdvancedPane.showOfflineExceptions);
+      setEventListener("offlineAppsList", "select",
+                      gAdvancedPane.offlineAppSelected);
+      setEventListener("offlineAppsListRemove", "command",
+                      gAdvancedPane.removeOfflineApp);
+      setEventListener("clearOfflineAppCacheButton", "command",
+                      gAdvancedPane.clearOfflineAppCache);
+      let bundlePrefs = document.getElementById("bundlePreferences");
+      document.getElementById("offlineAppsList")
+              .style.height = bundlePrefs.getString("offlineAppsList.height");
+      let offlineGroup = document.getElementById("offlineGroup");
+      offlineGroup.hidden = false;
+    }
+
     if (AppConstants.MOZ_WIDGET_GTK) {
       // GTK tabbox' allow the scroll wheel to change the selected tab,
       // but we don't want this behavior for the in-content preferences.
       let tabsElement = document.getElementById("tabsElement");
       tabsElement.addEventListener("DOMMouseScroll", event => {
         event.stopPropagation();
       }, true);
     }
@@ -393,42 +398,16 @@ var gAdvancedPane = {
     try {
       var cacheService =
         Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
                   .getService(Components.interfaces.nsICacheStorageService);
       cacheService.asyncGetDiskConsumption(this.observer);
     } catch (e) {}
   },
 
-  // Retrieves the amount of space currently used by offline cache
-  updateActualAppCacheSize() {
-    var visitor = {
-      onCacheStorageInfo(aEntryCount, aConsumption, aCapacity, aDiskDirectory) {
-        var actualSizeLabel = document.getElementById("actualAppCacheSize");
-        var sizeStrings = DownloadUtils.convertByteUnits(aConsumption);
-        var prefStrBundle = document.getElementById("bundlePreferences");
-        // The XBL binding for the string bundle may have been destroyed if
-        // the page was closed before this callback was executed.
-        if (!prefStrBundle.getFormattedString) {
-          return;
-        }
-        var sizeStr = prefStrBundle.getFormattedString("actualAppCacheSize", sizeStrings);
-        actualSizeLabel.value = sizeStr;
-      }
-    };
-
-    try {
-      var cacheService =
-        Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
-                  .getService(Components.interfaces.nsICacheStorageService);
-      var storage = cacheService.appCacheStorage(LoadContextInfo.default, null);
-      storage.asyncVisitStorage(visitor, false);
-    } catch (e) {}
-  },
-
   updateCacheSizeUI(smartSizeEnabled) {
     document.getElementById("useCacheBefore").disabled = smartSizeEnabled;
     document.getElementById("cacheSize").disabled = smartSizeEnabled;
     document.getElementById("useCacheAfter").disabled = smartSizeEnabled;
   },
 
   readSmartSizeEnabled() {
     // The smart_size.enabled preference element is inverted="true", so its
@@ -470,27 +449,16 @@ var gAdvancedPane = {
     try {
       var cache = Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
                             .getService(Components.interfaces.nsICacheStorageService);
       cache.clear();
     } catch (ex) {}
     this.updateActualCacheSize();
   },
 
-  /**
-   * Clears the application cache.
-   */
-  clearOfflineAppCache() {
-    Components.utils.import("resource:///modules/offlineAppCache.jsm");
-    OfflineAppCacheHelper.clear();
-
-    this.updateActualAppCacheSize();
-    this.updateOfflineApps();
-  },
-
   clearSiteData() {
     let flags =
       Services.prompt.BUTTON_TITLE_IS_STRING * Services.prompt.BUTTON_POS_0 +
       Services.prompt.BUTTON_TITLE_CANCEL * Services.prompt.BUTTON_POS_1 +
       Services.prompt.BUTTON_POS_0_DEFAULT;
     let prefStrBundle = document.getElementById("bundlePreferences");
     let title = prefStrBundle.getString("clearSiteDataPromptTitle");
     let text = prefStrBundle.getString("clearSiteDataPromptText");
@@ -498,16 +466,55 @@ var gAdvancedPane = {
 
     let result = Services.prompt.confirmEx(
       window, title, text, flags, btn0Label, null, null, null, {});
     if (result == 0) {
       SiteDataManager.removeAll();
     }
   },
 
+  // Methods for Offline Apps(Appcache)
+
+  /**
+   * Clears the application cache.
+   */
+  clearOfflineAppCache() {
+    Components.utils.import("resource:///modules/offlineAppCache.jsm");
+    OfflineAppCacheHelper.clear();
+
+    this.updateActualAppCacheSize();
+    this.updateOfflineApps();
+  },
+
+  // Retrieves the amount of space currently used by offline cache
+  updateActualAppCacheSize() {
+    var visitor = {
+      onCacheStorageInfo(aEntryCount, aConsumption, aCapacity, aDiskDirectory) {
+        var actualSizeLabel = document.getElementById("actualAppCacheSize");
+        var sizeStrings = DownloadUtils.convertByteUnits(aConsumption);
+        var prefStrBundle = document.getElementById("bundlePreferences");
+        // The XBL binding for the string bundle may have been destroyed if
+        // the page was closed before this callback was executed.
+        if (!prefStrBundle.getFormattedString) {
+          return;
+        }
+        var sizeStr = prefStrBundle.getFormattedString("actualAppCacheSize", sizeStrings);
+        actualSizeLabel.value = sizeStr;
+      }
+    };
+
+    try {
+      var cacheService =
+        Components.classes["@mozilla.org/netwerk/cache-storage-service;1"]
+                  .getService(Components.interfaces.nsICacheStorageService);
+      var storage = cacheService.appCacheStorage(LoadContextInfo.default, null);
+      storage.asyncVisitStorage(visitor, false);
+    } catch (e) {}
+  },
+
   readOfflineNotify() {
     var pref = document.getElementById("browser.offline-apps.notify");
     var button = document.getElementById("offlineNotifyExceptions");
     button.disabled = !pref.value;
     return pref.value;
   },
 
   showOfflineExceptions() {
@@ -641,16 +648,17 @@ var gAdvancedPane = {
       } catch (e) {}
 
       pm.removePermission(perm);
     }
     list.removeChild(item);
     gAdvancedPane.offlineAppSelected();
     this.updateActualAppCacheSize();
   },
+  // Methods for Offline Apps(Appcache) end
 
   // UPDATE TAB
 
   /*
    * Preferences:
    *
    * app.update.enabled
    * - true if updates to the application are enabled, false otherwise

--- a/browser/components/preferences/in-content/advanced.xul
+++ b/browser/components/preferences/in-content/advanced.xul
@@ -286,17 +286,17 @@
           </label>
           <textbox id="cacheSize" type="number" size="4" max="1024"
                    aria-labelledby="useCacheBefore cacheSize useCacheAfter"/>
           <label id="useCacheAfter" flex="1">&limitCacheSizeAfter.label;</label>
         </hbox>
       </groupbox>
 
       <!-- Offline apps -->
-      <groupbox id="offlineGroup">
+      <groupbox id="offlineGroup" hidden="true">
         <caption><label>&offlineStorage2.label;</label></caption>
 
         <hbox align="center">
           <label id="actualAppCacheSize" flex="1"/>
           <button id="clearOfflineAppCacheButton" icon="clear"
                   label="&clearOfflineAppCacheNow.label;" accesskey="&clearOfflineAppCacheNow.accesskey;"/>
         </hbox>
         <hbox align="center">