Add tests to EnhancedBookmarksModel

Enhanced bookmark model is the data abstraction layer of enhanced bookmark.

This CL also fixes the bug that add folder returns a wrong bookmarkid.

BUG=458632, 458703

Review URL: https://codereview.chromium.org/929523002

Cr-Commit-Position: refs/heads/master@{#318718}

chrome/android/java/src/org/chromium/chrome/browser/enhanced_bookmarks/EnhancedBookmarksModel.java

@@ -5,6 +5,7 @@
 package org.chromium.chrome.browser.enhanced_bookmarks;
 
 import org.chromium.base.ObserverList;
+import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.BookmarksBridge;
 import org.chromium.chrome.browser.BookmarksBridge.BookmarkItem;
 import org.chromium.chrome.browser.BookmarksBridge.BookmarkModelObserver;
@@ -63,6 +64,12 @@ public class EnhancedBookmarksModel {
         this();
     }
 
+    @VisibleForTesting
+    EnhancedBookmarksModel(Profile profile) {
+        mBookmarksBridge = new BookmarksBridge(profile);
+        mEnhancedBookmarksBridge = new EnhancedBookmarksBridge(profile);
+    }
+
     /**
      * Clean up all the bridges. This must be called after done using this class.
      */
@@ -275,7 +282,8 @@ public class EnhancedBookmarksModel {
     }
 
     /**
-     * @see EnhancedBookmarksBridge#moveBookmark(BookmarkId, BookmarkId)
+     * Calls {@link EnhancedBookmarksBridge#moveBookmark(BookmarkId, BookmarkId)} in a reversed
+     * order of the list, in order to let the last item appear at the top.
      */
     public void moveBookmarks(List<BookmarkId> bookmarkIds, BookmarkId newParentId) {
         for (int i = bookmarkIds.size() - 1; i >= 0; i--) {
@@ -394,4 +402,12 @@ public class EnhancedBookmarksModel {
     public void removeSearchObserver(SearchServiceObserver observer) {
         mEnhancedBookmarksBridge.removeSearchObserver(observer);
     }
+
+    /**
+     * @see BookmarksBridge#loadEmptyPartnerBookmarkShimForTesting()
+     */
+    @VisibleForTesting
+    public void loadEmptyPartnerBookmarkShimForTesting() {
+        mBookmarksBridge.loadEmptyPartnerBookmarkShimForTesting();
+    }
 }