Ensure all AssociatedURLLoader be cancelled before shutting down Blink.

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 cdbb75493d211e6156218d474d9af436af22effd..907eae7ab2056a75fb56e9eb16e8d8dce1419a12 100644
--- a/content/renderer/image_downloader/image_downloader_impl.h
+++ b/content/renderer/image_downloader/image_downloader_impl.h
@@ -13,6 +13,7 @@
 #include "base/memory/scoped_vector.h"
 #include "content/common/image_downloader/image_downloader.mojom.h"
 #include "content/public/renderer/render_frame_observer.h"
+#include "content/public/renderer/render_process_observer.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "url/gurl.h"
 
@@ -28,12 +29,16 @@ class MultiResolutionImageResourceFetcher;
 class RenderFrame;
 
 class ImageDownloaderImpl : public content::mojom::ImageDownloader,
-                            public RenderFrameObserver {
+                            public RenderFrameObserver,
+                            public RenderProcessObserver {
  public:
   static void CreateMojoService(
       RenderFrame* render_frame,
       mojo::InterfaceRequest<content::mojom::ImageDownloader> request);
 
+  // RenderProcessObserver implementation.
+  void OnRenderProcessShutdown() override;
+
  private:
   ImageDownloaderImpl(
       RenderFrame* render_frame,