Revert of Revert of Add a parameter to FileStreamWriter::CreateForLocalFile to allow creating new (https://codereview.chromium.org/206073006/)

Reason for revert:
Sorry, I looked through this CL in more detail and it seems that it doesn't change any behavior.

Re-reverting this one and instead trying crrev.com/258064

Original issue's description:
> Revert of Add a parameter to FileStreamWriter::CreateForLocalFile to allow creating new (https://codereview.chromium.org/197233008/)
> 
> Reason for revert:
> Best guess that this broke
> SyncFileSystemApiTest.WriteFileThenGetUsage
> on XP Tests(1).
> 
> http://build.chromium.org/p/chromium.win/builders/XP%20Tests%20%281%29/builds/30601/steps/browser_tests/logs/WriteFileThenGetUsage
> 
> If not, we can just re-revert or reland it after a few cycles.
> 
> Original issue's description:
> > Add a parameter to FileStreamWriter::CreateForLocalFile to allow creating new files as well as writing to existing files.
> > See https://codereview.chromium.org/18023022/ for context; this is needed by upcoming IDB Blob support.
> > 
> > Tzik, please do primary review for filesystem; Kinaba, please review as ChromeOS owner.
> > 
> > BUG=108012
> > R=kinaba,tzik
> > 
> > Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=258120
> 
> TBR=kinaba@chromium.org,tzik@chromium.org,ericu@chromium.org
> NOTREECHECKS=true
> NOTRY=true
> BUG=108012
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=258256

TBR=kinaba@chromium.org,tzik@chromium.org,ericu@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=108012

Review URL: https://codereview.chromium.org/206083004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@258259 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 1 deletions

diff --git a/webkit/browser/fileapi/file_stream_writer.h b/webkit/browser/fileapi/file_stream_writer.h
index 1ebdfb9..3a30ab2 100644
--- a/webkit/browser/fileapi/file_stream_writer.h
+++ b/webkit/browser/fileapi/file_stream_writer.h
@@ -23,12 +23,15 @@ namespace fileapi {
 // A generic interface for writing to a file-like object.
 class FileStreamWriter {
  public:
+  enum OpenOrCreate { OPEN_EXISTING_FILE, CREATE_NEW_FILE };
+
   // Creates a writer for the existing file in the path |file_path| starting
   // from |initial_offset|. Uses |task_runner| for async file operations.
   WEBKIT_STORAGE_BROWSER_EXPORT static FileStreamWriter* CreateForLocalFile(
       base::TaskRunner* task_runner,
       const base::FilePath& file_path,
-      int64 initial_offset);
+      int64 initial_offset,
+      OpenOrCreate open_or_create);
 
   // Closes the file. If there's an in-flight operation, it is canceled (i.e.,
   // the callback function associated with the operation is not called).