Avoid sync IPCs for FileSystem API

chrome/renderer/content_settings_observer.h

Index: chrome/renderer/content_settings_observer.h
diff --git a/chrome/renderer/content_settings_observer.h b/chrome/renderer/content_settings_observer.h
index 53548b8dca1b260b5646d36d5d5b4e701610edea..c06a5c62c9dd840849687a3321038d360dbb6b43 100644
--- a/chrome/renderer/content_settings_observer.h
+++ b/chrome/renderer/content_settings_observer.h
@@ -54,6 +54,9 @@ class ContentSettingsObserver
                              const blink::WebString& display_name,
                              unsigned long estimated_size);
   virtual bool allowFileSystem(blink::WebFrame* frame);
+  virtual void requestFileSystemAccess(
+      blink::WebFrame* frame,
+      const blink::WebPermissionCallbacks& callbacks);
   virtual bool allowImage(blink::WebFrame* frame,
                           bool enabled_per_settings,
                           const blink::WebURL& image_url);
@@ -109,6 +112,7 @@ class ContentSettingsObserver
   void OnSetAllowDisplayingInsecureContent(bool allow);
   void OnSetAllowRunningInsecureContent(bool allow);
   void OnReloadFrame();
+  void OnRequestFileSystemAccessResponse(int request_id, bool allowed);
 
   // Resets the |content_blocked_| array.
   void ClearBlockedContentSettings();
@@ -152,6 +156,10 @@ class ContentSettingsObserver
   bool is_interstitial_page_;
   bool npapi_plugins_blocked_;
 
+  int current_request_id_;
+  typedef std::map<int, blink::WebPermissionCallbacks> PermissionRequestMap;
+  PermissionRequestMap permission_requests_;
+
   DISALLOW_COPY_AND_ASSIGN(ContentSettingsObserver);
 };