Add methods to Reading List Model

ios/chrome/browser/reading_list/reading_list_model.h

Index: ios/chrome/browser/reading_list/reading_list_model.h
diff --git a/ios/chrome/browser/reading_list/reading_list_model.h b/ios/chrome/browser/reading_list/reading_list_model.h
index 40b3551e857969734016763869ee7e7e72f20073..76628c1b0cb869c29666679f141c8882e41de195 100644
--- a/ios/chrome/browser/reading_list/reading_list_model.h
+++ b/ios/chrome/browser/reading_list/reading_list_model.h
@@ -79,6 +79,10 @@ class ReadingListModel {
   // the reading list and read, move it to the top of unread if it is not here
   // already. This may trigger deletion of old read entries.
   virtual void MarkReadByURL(const GURL& url) = 0;
+  // If the |url| is in the reading list and read, mark it unread. If it is in
+  // the reading list and unread, move it to the top of read if it is not here
+  // already.
+  virtual void MarkUnreadByURL(const GURL& url) = 0;
 
   // Methods to mutate an entry. Will locate the relevant entry by URL. Does
   // nothing if the entry is not found.
@@ -108,6 +112,9 @@ class ReadingListModel {
     DISALLOW_COPY_AND_ASSIGN(ScopedReadingListBatchUpdate);
   };
 
+  // Remove all reading list entries. Used for tests only.

[Olivier, 2016/10/20 11:25:39]

Removes
Do you need this in the public interface?

[gambard, 2016/10/20 11:51:35]

Done.
I need this for EG test. If you see a better place, please tell.

[Olivier, 2016/10/20 13:38:02]

Unittests use directly ReadingListModelImpl, so you don't need the definition
here.
Alternatively, as there is nothing private in the method and you can add a
egtest helper that does this

while (model->unread_size()) {
 model_->RemoveEntryByUrl(GetUnreadEntryAtIndex(0).url());

[gambard, 2016/10/20 15:43:05]

Done.

+  virtual void ClearModelForTest() = 0;
+
  protected:
   ReadingListModel();
   virtual ~ReadingListModel();