chrome: Use stl utilities from the base namespace

chrome/browser/sync_file_system/local/local_file_sync_context.cc

Index: chrome/browser/sync_file_system/local/local_file_sync_context.cc
diff --git a/chrome/browser/sync_file_system/local/local_file_sync_context.cc b/chrome/browser/sync_file_system/local/local_file_sync_context.cc
index 3ecc82f1e6ee3ad354bd3c9f41dad4311572f26d..db114e2cf4462b2724a9874d5ed78cb6927c0a19 100644
--- a/chrome/browser/sync_file_system/local/local_file_sync_context.cc
+++ b/chrome/browser/sync_file_system/local/local_file_sync_context.cc
@@ -68,7 +68,7 @@ void LocalFileSyncContext::MaybeInitializeFileSystemContext(
     FileSystemContext* file_system_context,
     const SyncStatusCallback& callback) {
   DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
-  if (ContainsKey(file_system_contexts_, file_system_context)) {
+  if (base::ContainsKey(file_system_contexts_, file_system_context)) {
     // The context has been already initialized. Just dispatch the callback
     // with SYNC_STATUS_OK.
     ui_task_runner_->PostTask(FROM_HERE, base::Bind(callback, SYNC_STATUS_OK));
@@ -741,8 +741,8 @@ void LocalFileSyncContext::DidInitialize(
     return;
   }
   DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
-  DCHECK(!ContainsKey(file_system_contexts_, file_system_context));
-  DCHECK(ContainsKey(pending_initialize_callbacks_, file_system_context));
+  DCHECK(!base::ContainsKey(file_system_contexts_, file_system_context));
+  DCHECK(base::ContainsKey(pending_initialize_callbacks_, file_system_context));
 
   SyncFileSystemBackend* backend =
       SyncFileSystemBackend::GetBackend(file_system_context);