Use appropriate FileSystemOperations in "filesystem:" URLRequestJobs.

FileSystemURLRequestJob now calls GetMetadata(), while FileSystemDirURLRequestJob
calls ReadDirectory().  With neither calling GetLocalPath(), the need for
FileSystemURLRequestJobBase has disappeared, as has the need for
FileSystemOperation::GetLocalPath and FileSystemCallbackDispatcher::DidGetLocalPath().

The only changes in behavior due to this patch are:
  - ReadDirectory is now called on the URL, so it will still work properly
    after the obsfuscated filesystem is in use.
  - FileSystemDirURLRequestJob has been fixed to show a directory header.
    This was somehow lost in the refactor to use FileSystemURLRequestJobBase.
  - The error codes for "file not found" are now always net::ERR_FILE_NOT_FOUND.

[email protected]

Review URL: http://codereview.chromium.org/7047013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86015 0039d316-1c4b-4281-b951-d872f2087c98
21 files changed