Reland: Stop passing raw pointers to base::Value API in c/b/chromeos and c/b/extensions

chrome/browser/extensions/api/sync_file_system/sync_file_system_api_helpers.cc

Index: chrome/browser/extensions/api/sync_file_system/sync_file_system_api_helpers.cc
diff --git a/chrome/browser/extensions/api/sync_file_system/sync_file_system_api_helpers.cc b/chrome/browser/extensions/api/sync_file_system/sync_file_system_api_helpers.cc
index 6cfbf8a18624f63dac91d052c1e69ffe49797346..c191b3d18a96a86eda90b25b611d32034b43009c 100644
--- a/chrome/browser/extensions/api/sync_file_system/sync_file_system_api_helpers.cc
+++ b/chrome/browser/extensions/api/sync_file_system/sync_file_system_api_helpers.cc
@@ -5,6 +5,8 @@
 #include "chrome/browser/extensions/api/sync_file_system/sync_file_system_api_helpers.h"
 
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/values.h"
 #include "storage/browser/fileapi/file_system_url.h"
 #include "storage/common/fileapi/file_system_util.h"
 
@@ -105,11 +107,11 @@ ConflictResolutionPolicyToExtensionEnum(
   return api::sync_file_system::CONFLICT_RESOLUTION_POLICY_NONE;
 }
 
-base::DictionaryValue* CreateDictionaryValueForFileSystemEntry(
+std::unique_ptr<base::DictionaryValue> CreateDictionaryValueForFileSystemEntry(
     const storage::FileSystemURL& url,
     sync_file_system::SyncFileType file_type) {
   if (!url.is_valid() || file_type == sync_file_system::SYNC_FILE_TYPE_UNKNOWN)
-    return NULL;
+    return nullptr;
 
   std::string file_path =
       base::FilePath(storage::VirtualPath::GetNormalizedFilePath(url.path()))
@@ -122,7 +124,7 @@ base::DictionaryValue* CreateDictionaryValueForFileSystemEntry(
     root_url.append("/");
   }
 
-  base::DictionaryValue* dict = new base::DictionaryValue;
+  auto dict = base::MakeUnique<base::DictionaryValue>();
   dict->SetString("fileSystemType",
                   storage::GetFileSystemTypeString(url.mount_type()));
   dict->SetString("fileSystemName",