FileAPI: Add WebFileSystem::resolveURL

public/platform/WebFileSystemCallbacks.h

Index: public/platform/WebFileSystemCallbacks.h
diff --git a/public/platform/WebFileSystemCallbacks.h b/public/platform/WebFileSystemCallbacks.h
index c8ab90b3fe19b08eb0d06ff437cab5dcce487a10..b7babd09d82a09a625f2861879059a156a82a89f 100644
--- a/public/platform/WebFileSystemCallbacks.h
+++ b/public/platform/WebFileSystemCallbacks.h
@@ -66,6 +66,11 @@ public:
     // root URL for the FileSystem when the request is accepted.
     virtual void didOpenFileSystem(const WebString& name, const WebURL& rootURL) = 0;
 
+    // Callback for WebFileSystem::resolveURL. Called with a name, root URL and
+    // file path for the FileSystem when the request is accepted. |isDirectory|
+    // must be true when an entry to be resolved is a directory.
+    virtual void didResolveURL(const WebString& name, const WebURL& rootURL, const WebString& filePath, bool isDirectory) = 0;
+
     // Callback for WebFileSystem::createFileWriter. Called with an instance
     // of WebFileWriter and the target file length. The writer's ownership
     // is transferred to the callback.