Don't abuse LevelDBObserver interface to pass GetAll result.

content/browser/leveldb_wrapper_impl.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 "content/browser/leveldb_wrapper_impl.h"
 
 #include "base/bind.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/leveldb/public/cpp/util.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 198 matching lines @@
   }
 
   auto found = map_->find(key);
   if (found == map_->end()) {
     callback.Run(false, std::vector<uint8_t>());
     return;
   }
   callback.Run(true, found->second);
 }
 
-void LevelDBWrapperImpl::GetAll(const std::string& source,
-                                const GetAllCallback& callback) {
+void LevelDBWrapperImpl::GetAll(
+    mojom::LevelDBWrapperGetAllCallbackAssociatedPtrInfo complete_callback,
+    const GetAllCallback& callback) {
   if (!map_) {
-    LoadMap(
-        base::Bind(&LevelDBWrapperImpl::GetAll, base::Unretained(this),
-                   source, callback));
+    LoadMap(base::Bind(&LevelDBWrapperImpl::GetAll, base::Unretained(this),
+                       base::Passed(std::move(complete_callback)), callback));

[dcheng, 2016/12/22 07:21:47]

Nit: base::Passed(&complete_callback)

[Marijn Kruisselbrink, 2016/12/22 17:12:19]

I find the std::move version of base::Passed more readable (and of course the
future with OnceCallback and std::move only would be even better. Did you make
any more progress on getting mojo bindings to use OnceCallback?)

     return;
   }
 
   std::vector<mojom::KeyValuePtr> all;
   for (const auto& it : (*map_)) {
     mojom::KeyValuePtr kv = mojom::KeyValue::New();
     kv->key = it.first;
     kv->value = it.second;
     all.push_back(std::move(kv));
   }
   callback.Run(leveldb::mojom::DatabaseError::OK, std::move(all));
-  observers_.ForAllPtrs(
-      [source](mojom::LevelDBObserver* observer) {
-        observer->GetAllComplete(source);
-      });
+  if (complete_callback.is_valid()) {
+    mojom::LevelDBWrapperGetAllCallbackAssociatedPtr complete_ptr;
+    complete_ptr.Bind(std::move(complete_callback));
+    complete_ptr->Complete(true);
+  }
 }
 
 void LevelDBWrapperImpl::OnConnectionError() {
   if (!bindings_.empty())
     return;
   no_bindings_callback_.Run();
 }
 
 void LevelDBWrapperImpl::LoadMap(const base::Closure& completion_callback) {
   DCHECK(!map_);
@@ skipping 114 matching lines @@
                               weak_ptr_factory_.GetWeakPtr()));
 }
 
 void LevelDBWrapperImpl::OnCommitComplete(leveldb::mojom::DatabaseError error) {
   // TODO(michaeln): What if it fails, uma here or in the DB class?
   --commit_batches_in_flight_;
   StartCommitTimer();
 }
 
 }  // namespace content