[Offline pages] Wiring saving and opening offline page

chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java b/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
index f2f936ca62617c79ab84fbc9d1b12ac3e7e9e9a8..a1f7e5bd3c13c492e891dee8212786612505d40a 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
@@ -7,6 +7,7 @@ package org.chromium.chrome.browser.enhancedbookmarks;
 import android.app.Activity;
 import android.preference.PreferenceManager;
 import android.support.v4.widget.DrawerLayout;
+import android.text.TextUtils;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.View;
@@ -394,11 +395,14 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
     public void openBookmark(BookmarkId bookmark, int launchLocation) {
         clearSelection();
         if (mEnhancedBookmarksModel.getBookmarkById(bookmark) != null) {
+            String url = mEnhancedBookmarksModel.getBookmarkLaunchUrl(bookmark);
+            // TODO(jianli): Notify the user about the failure.
+            if (TextUtils.isEmpty(url)) return;
+
             NewTabPageUma.recordAction(NewTabPageUma.ACTION_OPENED_BOOKMARK);
             RecordHistogram.recordEnumeratedHistogram("Stars.LaunchLocation", launchLocation,
                     LaunchLocation.COUNT);
-            EnhancedBookmarkUtils.openBookmark(mActivity,
-                    mEnhancedBookmarksModel.getBookmarkById(bookmark).getUrl());
+            EnhancedBookmarkUtils.openBookmark(mActivity, url);
             finishActivityOnPhone();
         }
     }