Support file system access in DevTools with isolated file system.

content/public/browser/devtools_frontend_host_delegate.h

Index: content/public/browser/devtools_frontend_host_delegate.h
diff --git a/content/public/browser/devtools_frontend_host_delegate.h b/content/public/browser/devtools_frontend_host_delegate.h
index 79d3d9f6d8cf7ddf5bc137d82d361dc1d5ef200e..7b4e44285ef220b1ed5f67cbca1118f0c3e4ebeb 100644
--- a/content/public/browser/devtools_frontend_host_delegate.h
+++ b/content/public/browser/devtools_frontend_host_delegate.h
@@ -42,6 +42,15 @@ class DevToolsFrontendHostDelegate {
   virtual void AppendToFile(const std::string& url,
                             const std::string& content) = 0;
 
+  // Requests the list of file systems added for devtools previously.
+  virtual void RequestFilesystems() = 0;
+
+  // Shows a dialog to select a folder to add an isolated file system for.
+  virtual void AddFilesystem() = 0;
+
+  // Removes previously added devtools file system by given |file_system_path|.
+  virtual void RemoveFilesystem(const std::string& file_system_path) = 0;
+
   // This method is called when the contents inspected by this devtools frontend
   // is closing.
   virtual void InspectedContentsClosing() = 0;