Menu hook plumbed through to RequestCoordinator.

chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java

Index: chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java
index ac5f96deea5ad4c38f75ea47857dbe79eed3f083..8a2c3af080829ec74a6c2ba8c3773c2b41ce392a 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java
@@ -16,11 +16,15 @@ import android.view.View.OnCreateContextMenuListener;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.metrics.RecordHistogram;
+import org.chromium.chrome.browser.offlinepages.ClientId;
+import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
 import org.chromium.chrome.browser.share.ShareHelper;
 import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.ui.base.WindowAndroid;
 
+import java.util.Date;
+
 /**
  * A helper class that handles generating context menus for {@link ContentViewCore}s.
  */
@@ -118,6 +122,16 @@ public class ContextMenuHelper implements OnCreateContextMenuListener, OnMenuIte
         ShareHelper.shareImage(activity, jpegImageData);
     }
 
+    /**
+     * Starts a task to save the linked URL as an offline page.
+     */
+    public void savePageLater(String url, OfflinePageBridge bridge) {
+        Date now = new Date();
+        long offline_id = now.getTime();
+        ClientId clientId = new ClientId("LinkLoader", Long.toString(offline_id));

[dougarnett, 2016/05/06 16:47:41]

Maybe "AsyncLoader" better namespace to start with (TODO - define string
someplace better)

[Pete Williamson, 2016/05/06 18:28:13]

Done. (You will see the change in TabContextMenuItemDelegate.java instead of
here since I moved it due to another piece of CR feedback).

+        bridge.savePageLater(url, clientId);
+    }
+
     @Override
     public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
         if (!shouldShowMenu(mCurrentContextMenuParams)) return;