mediaview: Fix ARC file system operation deferring.

chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.cc

Index: chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.cc
diff --git a/chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.cc b/chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.cc
index b13ff288099efa2df6610b62d851f0fa833dd9b5..ac320de58e44e6ba77cc6868edc3c376ef6b4fcc 100644
--- a/chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.cc
+++ b/chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.cc
@@ -34,6 +34,8 @@ void GetFileSizeOnUIThread(const GURL& url,
   auto* runner =
       ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
   if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
+               << "File system operations are dropped.";
     callback.Run(-1);

[hidehiko, 2017/02/23 08:36:04]

(Not due to this change but) Looks a bug (missing return)?
If you'd like, I'm ok to leave this as is in this CL, and to address it in
another CL.

[Shuhei Takahashi, 2017/02/23 08:49:30]

Great catch! Let's fix it now.

   }
   runner->GetFileSize(url, callback);
@@ -45,6 +47,8 @@ void OpenFileToReadOnUIThread(const GURL& url,
   auto* runner =
       ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
   if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
+               << "File system operations are dropped.";
     callback.Run(mojo::ScopedHandle());
     return;
   }
@@ -58,6 +62,8 @@ void GetDocumentOnUIThread(const std::string& authority,
   auto* runner =
       ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
   if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
+               << "File system operations are dropped.";
     callback.Run(mojom::DocumentPtr());
     return;
   }
@@ -71,6 +77,8 @@ void GetChildDocumentsOnUIThread(const std::string& authority,
   auto* runner =
       ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
   if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
+               << "File system operations are dropped.";
     callback.Run(base::nullopt);
     return;
   }