[Offline pages] Refactor createClientIdForTabSharing and ClientId/UUID creation

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java

 // Copyright 2015 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.
 
 package org.chromium.chrome.browser.offlinepages;
 
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
@@ skipping 342 matching lines @@
      * @return a callback of OfflinePageItem
      */
     private static Callback<OfflinePageItem> selectPageForOnlineUrlCallback(
             final WebContents webContents, final OfflinePageBridge offlinePageBridge,
             final Callback<OfflinePageItem> prepareForSharing) {
         return new Callback<OfflinePageItem>() {
             @Override
             public void onResult(OfflinePageItem item) {
                 if (item == null) {
                     // If the page has no offline copy, save the page offline.
-                    ClientId clientId = ClientId.createClientIdForTabSharing();
+                    ClientId clientId = ClientId.createGuidClientIdForNamespace(
+                            OfflinePageBridge.SHARE_NAMESPACE);
                     offlinePageBridge.savePage(webContents, clientId,
                             savePageCallback(prepareForSharing, offlinePageBridge));
                     return;
                 }
                 // If the online page has offline copy associated with it, use the file directly.
                 prepareForSharing.onResult(item);
             }
         };
     }
 
@@ skipping 205 matching lines @@
     @VisibleForTesting
     static void setInstanceForTesting(OfflinePageUtils instance) {
         sInstance = instance;
     }
 
     @VisibleForTesting
     public static void setSnackbarDurationForTesting(int durationMs) {
         sSnackbarDurationMs = durationMs;
     }
 }