GitLab

This CL adds
1- Handle reading list bookmark type in BookmarkId string serialization.
Serialized string ids will have 'r' prefix, similar to 'p' prefix
in partner bookmarks.
2- Added missing reading list type to BookmarkBridge::DoesBookmarkExist
3- Added missing reading list type to BookmarkBridge::DeleteBookmark.

Bug: 1139070
Change-Id: If34fc167ad5d92f22e13f941f55a04f9bea2bd0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2524704
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825486}