components: add wifi_sync component

components/wifi_sync/wifi_credential_syncable_service.cc

+// Copyright 2014 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/wifi_sync/wifi_credential_syncable_service.h"
+
+namespace wifi_sync {
+
+// static
+const enum syncer::ModelType WifiCredentialSyncableService::kModelType =

[erikwright (departed), 2014/11/17 20:18:57]

I'm not used to seeing 'enum' somewhere like this. I would remove it unless you
see examples or have reasons to the contrary.

[mukesh agrawal, 2014/11/18 17:17:43]

Done.

+    syncer::WIFI_CREDENTIALS;
+
+WifiCredentialSyncableService::WifiCredentialSyncableService(
+    content::BrowserContext *context) :
+    browser_context_(context),
+    thread_checker_() {

[erikwright (departed), 2014/11/17 20:18:57]

not required

[mukesh agrawal, 2014/11/18 17:17:43]

Without the explicit initialization of thread_checker_, building fails with the
following error:

../../components/wifi_sync/wifi_credential_syncable_service.cc:13:32: error:
constructor for 'wifi_sync::WifiCredentialSyncableService' must explicitly
initialize the const member 'thread_checker_'
WifiCredentialSyncableService::WifiCredentialSyncableService(
                               ^
../../components/wifi_sync/wifi_credential_syncable_service.h:80:29: note:
'thread_checker_' declared here
  const base::ThreadChecker thread_checker_;

This happens when compiling using clang++ and goma.

Apparently, this is because "If a program calls for the default initialization
of an object of a const-qualified type T, T shall be a class type with a
user-provided default constructor.", and base::ThreadChecker does not have a
user-provided default constructor. (http://stackoverflow.com/a/24943751)

Alternatively, I could declare thread_checker_ non-const, or I could add a
user-provided default constructor to base::ThreadChecker.

Which solution would you recommend? (Leave code as-is, declare member non-const,
add ctor to base::ThreadChecker, or something else.)

+}
+
+WifiCredentialSyncableService::~WifiCredentialSyncableService() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+// Implementation of syncer::SyncableService API.
+syncer::SyncMergeResult WifiCredentialSyncableService::MergeDataAndStartSyncing(
+    syncer::ModelType type,
+    const syncer::SyncDataList& initial_sync_data,
+    scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
+    scoped_ptr<syncer::SyncErrorFactory> error_handler) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!sync_processor_.get());
+  DCHECK(sync_processor.get());
+  DCHECK(error_handler.get());
+  DCHECK_EQ(kModelType, type);
+
+  sync_processor_ = sync_processor.Pass();
+  sync_error_handler_ = error_handler.Pass();
+
+  return syncer::SyncMergeResult(type);

[erikwright (departed), 2014/11/17 20:18:57]

IWYU

[mukesh agrawal, 2014/11/18 17:17:43]

Done.

+}
+
+void WifiCredentialSyncableService::StopSyncing(syncer::ModelType type) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(kModelType, type);
+  sync_processor_.reset();
+  sync_error_handler_.reset();
+}
+
+syncer::SyncDataList WifiCredentialSyncableService::GetAllSyncData(
+    syncer::ModelType type) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(kModelType, type);
+  NOTIMPLEMENTED();
+  return syncer::SyncDataList();

[erikwright (departed), 2014/11/17 20:18:57]

IWYU

[mukesh agrawal, 2014/11/18 17:17:43]

Done.

+}
+
+syncer::SyncError WifiCredentialSyncableService::ProcessSyncChanges(
+    const tracked_objects::Location& from_here,
+    const syncer::SyncChangeList& change_list) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  NOTIMPLEMENTED();

[erikwright (departed), 2014/11/17 20:18:57]

base/logging.h

[mukesh agrawal, 2014/11/18 17:17:43]

Done.

+  return syncer::SyncError();

[erikwright (departed), 2014/11/17 20:18:57]

this, on the other hand, will require a full type and (assuming you remove it
from the .h) an include

[mukesh agrawal, 2014/11/18 17:17:43]

Done.

+}
+
+// Test support.
+WifiCredentialSyncableService::WifiSsidSecuritySet
+WifiCredentialSyncableService::GetWifiNetworksForTest() const {
+  return WifiSsidSecuritySet();
+}
+
+}  // namespace wifi_sync