Introduce AsyncFileUtil and deprecate FileSystemFileUtilProxy

In LocalFileSystemOperation we used to use a synchronous implementation
(implemented as FileSystemFileUtil) to perform subtasks (e.g. file_util::Copy
type operation), but it's not always natural to have synchronous
implementation depending on filesystem types. For example async interface
works much better if we need to talk to a remote server or a device.

This patch introduces an async version of FileUtil, AsyncFileUtil,
and replaces FileSystemFileUtil+Proxy implementation with it.

After this patch, each filesystem can choose either:
- implement synchronous FileSystemFileUtil and use it with AsyncFileUtilAdapter, or
- directly implement asynchronous AsyncFileUtil

BUG=154835
TEST=existing tests

Review URL: https://codereview.chromium.org/12035049

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@179299 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 14 insertions, 3 deletions

diff --git a/webkit/chromeos/fileapi/cros_mount_point_provider.cc b/webkit/chromeos/fileapi/cros_mount_point_provider.cc
index 9a8aafb..49cf541 100644
--- a/webkit/chromeos/fileapi/cros_mount_point_provider.cc
+++ b/webkit/chromeos/fileapi/cros_mount_point_provider.cc
@@ -18,6 +18,7 @@
 #include "webkit/chromeos/fileapi/file_access_permissions.h"
 #include "webkit/chromeos/fileapi/remote_file_stream_writer.h"
 #include "webkit/chromeos/fileapi/remote_file_system_operation.h"
+#include "webkit/fileapi/async_file_util_adapter.h"
 #include "webkit/fileapi/external_mount_points.h"
 #include "webkit/fileapi/file_system_file_stream_reader.h"
 #include "webkit/fileapi/file_system_operation_context.h"
@@ -52,7 +53,8 @@ CrosMountPointProvider::CrosMountPointProvider(
     fileapi::ExternalMountPoints* system_mount_points)
     : special_storage_policy_(special_storage_policy),
       file_access_permissions_(new FileAccessPermissions()),
-      local_file_util_(new fileapi::IsolatedFileUtil()),
+      local_file_util_(new fileapi::AsyncFileUtilAdapter(
+          new fileapi::IsolatedFileUtil())),
       mount_points_(mount_points),
       system_mount_points_(system_mount_points) {
 }
@@ -236,6 +238,13 @@ fileapi::FileSystemFileUtil* CrosMountPointProvider::GetFileUtil(
     fileapi::FileSystemType type) {
   DCHECK(type == fileapi::kFileSystemTypeNativeLocal ||
          type == fileapi::kFileSystemTypeRestrictedNativeLocal);
+  return local_file_util_->sync_file_util();
+}
+
+fileapi::AsyncFileUtil* CrosMountPointProvider::GetAsyncFileUtil(
+    fileapi::FileSystemType type) {
+  DCHECK(type == fileapi::kFileSystemTypeNativeLocal ||
+         type == fileapi::kFileSystemTypeRestrictedNativeLocal);
   return local_file_util_.get();
 }
 
diff --git a/webkit/chromeos/fileapi/cros_mount_point_provider.h b/webkit/chromeos/fileapi/cros_mount_point_provider.h
index d34c209..f013e6b 100644
--- a/webkit/chromeos/fileapi/cros_mount_point_provider.h
+++ b/webkit/chromeos/fileapi/cros_mount_point_provider.h
@@ -18,11 +18,11 @@
 #include "webkit/storage/webkit_storage_export.h"
 
 namespace fileapi {
+class AsyncFileUtilAdapter;
 class ExternalMountPoints;
 class FileSystemFileUtil;
 class FileSystemURL;
 class IsolatedContext;
-class LocalFileUtil;
 }
 
 namespace chromeos {
@@ -63,6 +63,8 @@ class WEBKIT_STORAGE_EXPORT CrosMountPointProvider
   virtual bool IsRestrictedFileName(const FilePath& filename) const OVERRIDE;
   virtual fileapi::FileSystemFileUtil* GetFileUtil(
       fileapi::FileSystemType type) OVERRIDE;
+  virtual fileapi::AsyncFileUtil* GetAsyncFileUtil(
+      fileapi::FileSystemType type) OVERRIDE;
   virtual fileapi::FilePermissionPolicy GetPermissionPolicy(
       const fileapi::FileSystemURL& url,
       int permissions) const OVERRIDE;
@@ -114,7 +116,7 @@ class WEBKIT_STORAGE_EXPORT CrosMountPointProvider
 
   scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_;
   scoped_ptr<FileAccessPermissions> file_access_permissions_;
-  scoped_ptr<fileapi::LocalFileUtil> local_file_util_;
+  scoped_ptr<fileapi::AsyncFileUtilAdapter> local_file_util_;
 
   // Mount points specific to the owning context.
   //