Add GetURLForBrowserTab method to the external file system backend.

webkit/browser/fileapi/file_system_backend.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_BACKEND_H_
 #define WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_BACKEND_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 29 matching lines @@
 // NOTE: when you implement a new FileSystemBackend for your own
 // FileSystem module, please contact to kinuko@chromium.org.
 //
 class STORAGE_EXPORT FileSystemBackend {
  public:
   // Callback for InitializeFileSystem.
   typedef base::Callback<void(const GURL& root_url,
                               const std::string& name,
                               base::File::Error error)>
       OpenFileSystemCallback;
+  typedef base::Callback<void(const GURL& url)> URLCallback;

[mtomasz, 2014/09/04 05:30:01]

nit: Comment is missing, but there is one for the callback above. I think we
should be consistent.

[hirono, 2014/09/04 06:10:59]

Done.

   virtual ~FileSystemBackend() {}
 
   // Returns true if this filesystem backend can handle |type|.
   // One filesystem backend may be able to handle multiple filesystem types.
   virtual bool CanHandleType(FileSystemType type) const = 0;
 
   // This method is called right after the backend is registered in the
   // FileSystemContext and before any other methods are called. Each backend can
   // do additional initialization which depends on FileSystemContext here.
   virtual void Initialize(FileSystemContext* context) = 0;
@@ skipping 90 matching lines @@
   virtual void GrantFileAccessToExtension(
       const std::string& extension_id,
       const base::FilePath& virtual_path) = 0;
   // Revokes file access from extension identified with |extension_id|.
   virtual void RevokeAccessForExtension(
         const std::string& extension_id) = 0;
   // Gets virtual path by known filesystem path. Returns false when filesystem
   // path is not exposed by this provider.
   virtual bool GetVirtualPath(const base::FilePath& file_system_path,
                               base::FilePath* virtual_path) = 0;
+  // Gets an redirect URL for browser tab. e.g. Google Drive URL for hosted

[mtomasz, 2014/09/04 05:30:01]

nit: an -> a

[hirono, 2014/09/04 06:10:59]

Done.

+  // documents. Returns empty URL if the entry does not have the redirect URL.
+  virtual void GetURLForBrowserTab(

[mtomasz, 2014/09/04 05:30:01]

Naming of this method is still confusing to me. Looking at the name I expect
GetURLForBrowserTab to return the url for browser tab. If empty string is
returned then I'm expecting that there is no URL for browser tab. I'd expect
that it returns always exactly that url which is used for browser url.

However, the actual behavior is different. As in the comment, it *redirects* the
default URL for browser tab.

How about renaming to GetRedirectURLForBrowserTab?

[hirono, 2014/09/04 06:10:59]

Done.

+      const storage::FileSystemURL& url,
+      const URLCallback& callback) = 0;

[mtomasz, 2014/09/04 05:30:01]

I just realized one thing. Is this safe? What if a FSP provider returns a
"chrome://evil" URL? Is it safe?

[hirono, 2014/09/04 06:10:59]

I added a comment to
ExternalFileSystemBackendDelegate::GetRedirectURLForBrowserTab.

 };
 
 }  // namespace storage
 
 #endif  // WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_BACKEND_H_