SyncFS: Introduce SyncFileSystemBackend

webkit/browser/fileapi/syncable/syncable_file_system_operation.cc

Index: webkit/browser/fileapi/syncable/syncable_file_system_operation.cc
diff --git a/webkit/browser/fileapi/syncable/syncable_file_system_operation.cc b/webkit/browser/fileapi/syncable/syncable_file_system_operation.cc
index b2568132aee4caf5f8b429f52b77f440f3b3b7ab..88d2c69597882168678114d3c126420c43d9b37f 100644
--- a/webkit/browser/fileapi/syncable/syncable_file_system_operation.cc
+++ b/webkit/browser/fileapi/syncable/syncable_file_system_operation.cc
@@ -14,6 +14,7 @@
 #include "webkit/browser/fileapi/syncable/local_file_sync_context.h"
 #include "webkit/browser/fileapi/syncable/syncable_file_operation_runner.h"
 #include "webkit/browser/fileapi/syncable/syncable_file_system_util.h"
+#include "webkit/browser/fileapi/syncable/syncable_sandbox_mount_point_provider.h"
 #include "webkit/common/blob/shareable_file_reference.h"
 
 using fileapi::FileSystemURL;
@@ -318,13 +319,16 @@ SyncableFileSystemOperation::SyncableFileSystemOperation(
                                operation_context.Pass()),
       url_(url) {
   DCHECK(file_system_context);
-  if (!file_system_context->sync_context()) {
+  SyncableSandboxMountPointProvider* provider =
+      SyncableSandboxMountPointProvider::GetProvider(file_system_context);
+  DCHECK(provider);
+  if (!provider->sync_context()) {
     // Syncable FileSystem is opened in a file system context which doesn't
     // support (or is not initialized for) the API.
     // Returning here to leave operation_runner_ as NULL.
     return;
   }
-  operation_runner_ = file_system_context->sync_context()->operation_runner();
+  operation_runner_ = provider->sync_context()->operation_runner();
   is_directory_operation_enabled_ = IsSyncFSDirectoryOperationEnabled();
 }