[Offline Pages] Delete associated page along with bookmark.

chrome/browser/android/offline_pages/offline_page_model_factory.cc

Index: chrome/browser/android/offline_pages/offline_page_model_factory.cc
diff --git a/chrome/browser/android/offline_pages/offline_page_model_factory.cc b/chrome/browser/android/offline_pages/offline_page_model_factory.cc
index 6201cc2d1194ebc55757dab6a6eb33c22beb7c2e..db0cc07799b4d816cf3fc0d3bb4c7b86b35c11f3 100644
--- a/chrome/browser/android/offline_pages/offline_page_model_factory.cc
+++ b/chrome/browser/android/offline_pages/offline_page_model_factory.cc
@@ -9,6 +9,7 @@
 #include "base/files/file_path.h"
 #include "base/memory/singleton.h"
 #include "base/sequenced_task_runner.h"
+#include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_constants.h"
@@ -23,6 +24,7 @@ OfflinePageModelFactory::OfflinePageModelFactory()
     : BrowserContextKeyedServiceFactory(
           "OfflinePageModel",
           BrowserContextDependencyManager::GetInstance()) {
+  DependsOn(BookmarkModelFactory::GetInstance());

[Dmitry Titov, 2016/08/01 23:46:58]

Hmm, I wonder if it's a right direction of the dependency. What will guarantee
that every time a BookmarkModel is removing a bookmark there is an
OfflinePageModel around to observe this?

Should the BookmarksModel depend on OfflinePageModel? When BookmarkModel is
constructed, it can create an OfflineModel and make it observer. This will
guarantee the OfflinePageModel is there.

WDYT?

 }
 
 // static
@@ -52,8 +54,10 @@ KeyedService* OfflinePageModelFactory::BuildServiceInstanceFor(
   base::FilePath archives_dir =
       profile->GetPath().Append(chrome::kOfflinePageArchivesDirname);
 
-  return new OfflinePageModelImpl(std::move(metadata_store), archives_dir,
-                                  background_task_runner);
+  OfflinePageModelImpl* model = new OfflinePageModelImpl(
+      std::move(metadata_store), archives_dir, background_task_runner);
+  BookmarkModelFactory::GetForProfile(profile)->AddObserver(model);
+  return model;
 }
 
 }  // namespace offline_pages