Cleanup FileSystemOperation for preparing for adding FSO-factory method

webkit/fileapi/file_system_operation_interface.h

Index: webkit/fileapi/file_system_operation_interface.h
diff --git a/webkit/fileapi/file_system_operation_interface.h b/webkit/fileapi/file_system_operation_interface.h
index 033abead4ec07aa9c34f4f887759370d304b8fe0..f9018f17e47c06cbbd97db0aa19d4ebbe7c1a7ae 100644
--- a/webkit/fileapi/file_system_operation_interface.h
+++ b/webkit/fileapi/file_system_operation_interface.h
@@ -20,6 +20,8 @@ class GURL;
 
 namespace fileapi {
 
+class FileSystemCallbackDispatcher;
+
 // The interface class for FileSystemOperation implementations.
 //
 // This interface defines file system operations required to implement
@@ -46,12 +48,6 @@ class FileSystemOperationInterface {
  public:
   virtual ~FileSystemOperationInterface() {}
 
-  // Opens a file system at |origin_url| of the |type|. Creates a new file
-  // system if |create| is true.
-  virtual void OpenFileSystem(const GURL& origin_url,
-                              fileapi::FileSystemType type,
-                              bool create) = 0;
-
   // Creates a file at |path|. If |exclusive| is true, an error is raised
   // in case a file is already present at the URL.
   virtual void CreateFile(const GURL& path,
@@ -105,6 +101,30 @@ class FileSystemOperationInterface {
   // part is filled with null bytes.
   virtual void Truncate(const GURL& path, int64 length) = 0;
 
+  // Tries to cancel the current operation [we support cancelling write or
+  // truncate only]. Reports failure for the current operation, then reports
+  // success for the cancel operation itself via the |cancel_dispatcher|.
+  //
+  // E.g. a typical cancel implementation would look like:
+  //
+  //   virtual void SomeOperationImpl::Cancel(
+  //       scoped_ptr<FileSystemCallbackDispatcher> cancel_dispatcher) {
+  //     // Abort the current inflight operation first.
+  //     ...
+  //
+  //     // Dispatch ABORT error for the current operation by calling
+  //     // DidFail() callback of the dispatcher attached to this operation.
+  //     // (dispatcher_ in this example)
+  //     dispatcher_->DidFail(base::PLATFORM_FILE_ERROR_ABORT);
+  //
+  //     // Dispatch 'success' for the cancel (or dispatch appropriate
+  //     // error code with DidFail() if the cancel has somehow failed).
+  //     cancel_dispatcher->DidSucceed();
+  //   }
+  //
+  virtual void Cancel(
+      scoped_ptr<FileSystemCallbackDispatcher> cancel_dispatcher) = 0;
+
   // Modifies timestamps of a file or directory at |path| with
   // |last_access_time| and |last_modified_time|. The function DOES NOT
   // create a file unlike 'touch' command on Linux.