Fix threading bugs in product label UI.

chrome/browser/ui/webui/chromeos/image_source.h

Index: chrome/browser/ui/webui/chromeos/image_source.h
diff --git a/chrome/browser/ui/webui/chromeos/image_source.h b/chrome/browser/ui/webui/chromeos/image_source.h
index 3db5d9bec90b5d153c3e278a1df6efe19d752ad8..ac19037acc88e716b5c58e18da9536e2ba1373c6 100644
--- a/chrome/browser/ui/webui/chromeos/image_source.h
+++ b/chrome/browser/ui/webui/chromeos/image_source.h
@@ -38,18 +38,21 @@ class ImageSource : public content::URLDataSource {
       const std::string& path,
       int render_process_id,
       int render_frame_id,
-      const content::URLDataSource::GotDataCallback& callback) override;
+      const content::URLDataSource::GotDataCallback& got_data_callback)
+      override;
+
   std::string GetMimeType(const std::string& path) const override;
 
  private:
-  void StartOnFileThread(
-      const std::string& path,
-      const content::URLDataSource::GotDataCallback& callback);
+  // Callback after attempting to start loading the image.
+  void LoadImageAttempted(
+      const content::URLDataSource::GotDataCallback& got_data_callback,
+      bool load_started);
 
   // Callback for user_manager::UserImageLoader.
   void ImageLoaded(
-    const content::URLDataSource::GotDataCallback& callback,
-    const user_manager::UserImage& user_image) const;
+      const content::URLDataSource::GotDataCallback& got_data_callback,
+      const user_manager::UserImage& user_image) const;
 
   // Checks whether we have allowed the image to be loaded.
   bool IsWhitelisted(const std::string& path) const;