Fixed memory leak in FileURLLoader/FileURLDirectoryLoader.

OnConnectionError should have been resetting both the data producer
as well as the client.

Bug: 958796
Change-Id: Ibc60dc05f7763e4ac61b43e445b5f2b40adc9246
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1733018Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Chris Mumford <cmumford@google.com>
Cr-Commit-Position: refs/heads/master@{#683745}

content/browser/file_url_loader_factory.cc

@@ -226,7 +226,9 @@ class FileURLDirectoryLoader
   }
 
   void OnConnectionError() {
+    data_producer_.reset();
     binding_.Close();
+    client_.reset();
     MaybeDeleteSelf();
   }
 
@@ -671,7 +673,9 @@ class FileURLLoader : public network::mojom::URLLoader {
   }
 
   void OnConnectionError() {
+    data_producer_.reset();
     binding_.Close();
+    client_.reset();
     MaybeDeleteSelf();
   }