[NTP] Propagate OfflineId from C++ for Downloads.

chrome/browser/android/ntp/ntp_snippets_bridge.cc

Index: chrome/browser/android/ntp/ntp_snippets_bridge.cc
diff --git a/chrome/browser/android/ntp/ntp_snippets_bridge.cc b/chrome/browser/android/ntp/ntp_snippets_bridge.cc
index 7f03d7f224e8761dee9f3aaaa40116b60adf40e3..3fb66a599003ab0445e67e70978bfbb17c06f7d8 100644
--- a/chrome/browser/android/ntp/ntp_snippets_bridge.cc
+++ b/chrome/browser/android/ntp/ntp_snippets_bridge.cc
@@ -81,15 +81,21 @@ ScopedJavaLocalRef<jobject> ToJavaSuggestionList(
         static_cast<int>(info->card_layout()));
     if (suggestion.id().category().IsKnownCategory(
             KnownCategories::DOWNLOADS) &&
-        suggestion.download_suggestion_extra() != nullptr &&
-        suggestion.download_suggestion_extra()->is_download_asset) {
-      Java_SnippetsBridge_setDownloadAssetDataForLastSuggestion(
-          env, result,
-          ConvertUTF8ToJavaString(
-              env,
-              suggestion.download_suggestion_extra()->target_file_path.value()),
-          ConvertUTF8ToJavaString(
-              env, suggestion.download_suggestion_extra()->mime_type));
+        suggestion.download_suggestion_extra() != nullptr) {
+      if (suggestion.download_suggestion_extra()->is_download_asset) {
+        Java_SnippetsBridge_setDownloadAssetDataForLastSuggestion(
+            env, result,
+            ConvertUTF8ToJavaString(env, suggestion.download_suggestion_extra()
+                                             ->target_file_path.value()),
+            ConvertUTF8ToJavaString(
+                env, suggestion.download_suggestion_extra()->mime_type));
+      } else {
+        // TODO(vitaliii): Pass |offline_page_id| as a numeric variable.

[Bernhard Bauer, 2016/11/16 17:04:02]

Any particular reason you're not doing that now?

[vitaliii, 2016/11/16 17:28:10]

Neither Mark nor I knew whether this was possible :)
But now I did it and it was really easy.
Thanks!

+        Java_SnippetsBridge_setDownloadOfflinePageDataForLastSuggestion(

[Bernhard Bauer, 2016/11/16 17:04:02]

I realize this is just following existing code, but this interface seems a bit
more complicated than necessary. Couldn't we have SnippetsBridge.addSuggestion()
return the newly added suggestion, and make these methods take just the
suggestion as a parameter?

[vitaliii, 2016/11/16 17:28:10]

I added a TODO (as per your following comment).

+            env, result,
+            ConvertUTF8ToJavaString(
+                env, suggestion.download_suggestion_extra()->offline_page_id));
+      }
     }
     if (suggestion.id().category().IsKnownCategory(
             KnownCategories::RECENT_TABS) &&