(Android) Blocking multiple scheduled downloads for the same URL

chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsNavigationDelegateImpl.java

Index: chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsNavigationDelegateImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsNavigationDelegateImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsNavigationDelegateImpl.java
index 69691489464e1e9188917ce3415ddf09f5965e91..275dd012694020f7219b9de8366d82194a7e867e 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsNavigationDelegateImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsNavigationDelegateImpl.java
@@ -6,6 +6,7 @@ package org.chromium.chrome.browser.suggestions;
 
 import android.app.Activity;
 
+import org.chromium.base.Callback;
 import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.browser.NativePageHost;
 import org.chromium.chrome.browser.UrlConstants;
@@ -17,6 +18,7 @@ import org.chromium.chrome.browser.ntp.snippets.KnownCategories;
 import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
 import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
 import org.chromium.chrome.browser.offlinepages.OfflinePageUtils;
+import org.chromium.chrome.browser.offlinepages.SavePageRequest;
 import org.chromium.chrome.browser.offlinepages.downloads.OfflinePageNotificationBridge;
 import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.chrome.browser.profiles.Profile;
@@ -186,8 +188,21 @@ public class SuggestionsNavigationDelegateImpl implements SuggestionsNavigationD
     }
 
     private void saveUrlForOffline(String url) {
-        OfflinePageNotificationBridge.showDownloadingToast(mActivity);
-        OfflinePageBridge.getForProfile(mProfile).savePageLater(
-                url, "ntp_suggestions", true /* userRequested */);
+        final String mUrl = url;
+        OfflinePageBridge.getForProfile(mProfile).getRequestsInQueue(
+                new Callback<SavePageRequest[]>() {
+                    @Override
+                    public void onResult(SavePageRequest[] requests) {
+                        OfflinePageNotificationBridge.showDownloadingToast(mActivity);
+                        for (int i = 0, len = requests.length; i < len; i++) {
+                            if (requests[i].getUrl().equals(mUrl)) {
+                                // Download was scheduled earlier,
+                                return;
+                            }
+                        }
+                        OfflinePageBridge.getForProfile(mProfile).savePageLater(
+                                mUrl, "ntp_suggestions", true /* userRequested */);
+                    }
+                });
     }
 }