[FileAPI] Remove Flush() on write completion on SandboxFileSystems

webkit/browser/fileapi/file_system_context.cc

Index: webkit/browser/fileapi/file_system_context.cc
diff --git a/webkit/browser/fileapi/file_system_context.cc b/webkit/browser/fileapi/file_system_context.cc
index 549293959aac5d891256b30ea686913989e7b98c..2bf6a0f14d1c24059d5151d045dd807710696f26 100644
--- a/webkit/browser/fileapi/file_system_context.cc
+++ b/webkit/browser/fileapi/file_system_context.cc
@@ -479,6 +479,17 @@ bool FileSystemContext::CanServeURLRequest(const FileSystemURL& url) const {
   return !is_incognito_ || !FileSystemContext::IsSandboxFileSystem(url.type());
 }
 
+bool FileSystemContext::ShouldFlushOnWriteCompletion(
+    FileSystemType type) const {
+  if (IsSandboxFileSystem(type)) {
+    // Disable Flush() for each write operation on SandboxFileSystems since it
+    // hurts the performance, assuming the FileSystems are stored in a local
+    // disk, we don't need to keep calling fsync() for it.

[kinuko, 2014/05/02 07:02:48]

Maybe... it'd be also better note that some non-sandbox filesystems that could
work on removable devices need flush to make sure its data is written out to the
disk?

[tzik, 2014/05/02 07:37:24]

Wrote some more about non-sandboxed filesystem.

+    return false;
+  }
+  return true;
+}
+
 void FileSystemContext::OpenPluginPrivateFileSystem(
     const GURL& origin_url,
     FileSystemType type,