Enable use_once_callback for //content/common/*.mojom

content/renderer/image_downloader/image_downloader_impl.h

Index: content/renderer/image_downloader/image_downloader_impl.h
diff --git a/content/renderer/image_downloader/image_downloader_impl.h b/content/renderer/image_downloader/image_downloader_impl.h
index f9cfb63858e0dfe57f27bb0e847cbc5299f483b4..e244dc44ec485dd337b36ba0cb3c3b189e077691 100644
--- a/content/renderer/image_downloader/image_downloader_impl.h
+++ b/content/renderer/image_downloader/image_downloader_impl.h
@@ -31,7 +31,7 @@ class ImageDownloaderImpl : public mojom::ImageDownloader,
                      bool is_favicon,
                      uint32_t max_bitmap_size,
                      bool bypass_cache,
-                     const DownloadImageCallback& callback) override;
+                     DownloadImageCallback callback) override;
 
   // Called when downloading finishes. All frames in |images| whose size <=
   // |max_image_size| will be returned through |callback|. If all of the frames
@@ -39,7 +39,7 @@ class ImageDownloaderImpl : public mojom::ImageDownloader,
   // |max_image_size| and is the only result. |max_image_size| == 0 is
   // interpreted as no max image size.
   void DidDownloadImage(uint32_t max_bitmap_size,
-                        const DownloadImageCallback& callback,
+                        DownloadImageCallback callback,
                         int32_t http_status_code,
                         const std::vector<SkBitmap>& images);