Revert of Showing previews UI for Offline Previews

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageBridge.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 org.chromium.base.Callback;
 import org.chromium.base.ObserverList;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
@@ skipping 385 matching lines @@
 
     /**
      * Retrieves the extra request header to reload the offline page.
      * @param webContents Contents of the page to reload.
      * @return The extra request header string.
      */
     public String getOfflinePageHeaderForReload(WebContents webContents) {
         return nativeGetOfflinePageHeaderForReload(mNativeOfflinePageBridge, webContents);
     }
 
-    /**
-     * @return True if an offline preview is being shown.
-     * @param webContents Contents of the page to check.
-     */
-    public boolean isShowingOfflinePreview(WebContents webContents) {
-        return nativeIsShowingOfflinePreview(mNativeOfflinePageBridge, webContents);
-    }
-
     private static class CheckPagesExistOfflineCallbackInternal {
         private Callback<Set<String>> mCallback;
 
         CheckPagesExistOfflineCallbackInternal(Callback<Set<String>> callback) {
             mCallback = callback;
         }
 
         @CalledByNative("CheckPagesExistOfflineCallbackInternal")
         public void onResult(String[] results) {
             Set<String> resultSet = new HashSet<>();
@@ skipping 106 matching lines @@
             String[] ids, Callback<Integer> callback);
     private native void nativeSelectPageForOnlineUrl(
             long nativeOfflinePageBridge, String onlineUrl, int tabId,
             Callback<OfflinePageItem> callback);
     private native void nativeSavePage(long nativeOfflinePageBridge, SavePageCallback callback,
             WebContents webContents, String clientNamespace, String clientId);
     private native void nativeSavePageLater(long nativeOfflinePageBridge, String url,
             String clientNamespace, String clientId, boolean userRequested);
     private native String nativeGetOfflinePageHeaderForReload(
             long nativeOfflinePageBridge, WebContents webContents);
-    private native boolean nativeIsShowingOfflinePreview(
-            long nativeOfflinePageBridge, WebContents webContents);
 }