Enable download page action for error page

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;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.content_public.browser.WebContents;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
 /**
  * Access gate to C++ side offline pages functionalities.
  */
 @JNINamespace("offline_pages::android")
 public class OfflinePageBridge {
+    public static final String ASYNC_NAMESPACE = "async_loading";
     public static final String BOOKMARK_NAMESPACE = "bookmark";
     public static final String SHARE_NAMESPACE = "share";
 
     /**
      * Retrieves the OfflinePageBridge for the given profile, creating it the first time
      * getForProfile is called for a given profile.  Must be called on the UI thread.
      *
      * @param profile The profile associated with the OfflinePageBridge to get.
      */
     public static OfflinePageBridge getForProfile(Profile profile) {
@@ skipping 354 matching lines @@
     }
 
     /**
      * @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);
     }
 
+    /**
+     * @return True if download button is being shown in the error page.
+     * @param webContents Contents of the page to check.
+     */
+    public boolean isShowingDownloadButtonInErrorPage(WebContents webContents) {
+        return nativeIsShowingDownloadButtonInErrorPage(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 107 matching lines @@
             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);
+    private native boolean nativeIsShowingDownloadButtonInErrorPage(
+            long nativeOfflinePageBridge, WebContents webContents);
 }