New snippets now replace old snippets and do not merge

components/ntp_snippets/ntp_snippets_database.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/ntp_snippets/ntp_snippets_database.h"
 
 #include <utility>
 
 #include "base/files/file_path.h"
 #include "components/leveldb_proto/proto_database_impl.h"
 #include "components/ntp_snippets/proto/ntp_snippets.pb.h"
 
 using leveldb_proto::ProtoDatabaseImpl;
 
 namespace {
 // Statistics are logged to UMA with this string as part of histogram name. They
 // can all be found under LevelDB.*.NTPSnippets. Changing this needs to
 // synchronize with histograms.xml, AND will also become incompatible with older
 // browsers still reporting the previous values.
 const char kDatabaseUMAClientName[] = "NTPSnippets";
 const char kImageDatabaseUMAClientName[] = "NTPSnippetImages";
 
 const char kSnippetDatabaseFolder[] = "snippets";
 const char kImageDatabaseFolder[] = "images";
-}
+}  // namespace
 
 namespace ntp_snippets {
 
 NTPSnippetsDatabase::NTPSnippetsDatabase(
     const base::FilePath& database_dir,
     scoped_refptr<base::SequencedTaskRunner> file_task_runner)
     : database_(
           new ProtoDatabaseImpl<SnippetProto>(file_task_runner)),
       database_initialized_(false),
       image_database_(
@@ skipping 82 matching lines @@
   image_database_->UpdateEntries(
       std::move(entries_to_save), base::MakeUnique<std::vector<std::string>>(),
       base::Bind(&NTPSnippetsDatabase::OnImageDatabaseSaved,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 void NTPSnippetsDatabase::DeleteImage(const std::string& snippet_id) {
   DeleteImagesImpl(base::MakeUnique<std::vector<std::string>>(1, snippet_id));
 }
 
+void NTPSnippetsDatabase::DeleteImages(const NTPSnippet::PtrVector& snippets) {
+  std::unique_ptr<std::vector<std::string>> keys_to_remove(
+      new std::vector<std::string>());
+  for (const std::unique_ptr<NTPSnippet>& snippet : snippets)
+    keys_to_remove->emplace_back(snippet->id());
+  DeleteImagesImpl(std::move(keys_to_remove));
+}
+
 void NTPSnippetsDatabase::OnDatabaseInited(bool success) {
   DCHECK(!database_initialized_);
   if (!success) {
     DVLOG(1) << "NTPSnippetsDatabase init failed.";
     OnDatabaseError();
     return;
   }
   database_initialized_ = true;
   if (IsInitialized())
     ProcessPendingLoads();
@@ skipping 111 matching lines @@
   database_->UpdateEntries(std::move(entries_to_save),
                            std::move(keys_to_remove),
                            base::Bind(&NTPSnippetsDatabase::OnDatabaseSaved,
                                       weak_ptr_factory_.GetWeakPtr()));
 }
 
 void NTPSnippetsDatabase::DeleteSnippetsImpl(
     std::unique_ptr<std::vector<std::string>> keys_to_remove) {
   DCHECK(IsInitialized());
 
-  DeleteImagesImpl(base::MakeUnique<std::vector<std::string>>(*keys_to_remove));
-
   std::unique_ptr<KeyEntryVector> entries_to_save(new KeyEntryVector());
   database_->UpdateEntries(std::move(entries_to_save),
                            std::move(keys_to_remove),
                            base::Bind(&NTPSnippetsDatabase::OnDatabaseSaved,
                                       weak_ptr_factory_.GetWeakPtr()));
 }
 
 void NTPSnippetsDatabase::LoadImageImpl(const std::string& snippet_id,
                                         const SnippetImageCallback& callback) {
   DCHECK(IsInitialized());
   image_database_->GetEntry(
       snippet_id,
       base::Bind(&NTPSnippetsDatabase::OnImageDatabaseLoaded,
                  weak_ptr_factory_.GetWeakPtr(), callback));
 }
 
 void NTPSnippetsDatabase::DeleteImagesImpl(
     std::unique_ptr<std::vector<std::string>> keys_to_remove) {
   DCHECK(IsInitialized());
 
   image_database_->UpdateEntries(
       base::MakeUnique<ImageKeyEntryVector>(), std::move(keys_to_remove),
       base::Bind(&NTPSnippetsDatabase::OnImageDatabaseSaved,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 }  // namespace ntp_snippets