Stop offline page resource throttle from intercepting non http(s) urls

chrome/browser/android/offline_pages/downloads/resource_throttle.cc

Index: chrome/browser/android/offline_pages/downloads/resource_throttle.cc
diff --git a/chrome/browser/android/offline_pages/downloads/resource_throttle.cc b/chrome/browser/android/offline_pages/downloads/resource_throttle.cc
index a09b33c4abf26c70f13b2834710a8b659e385148..d4d1d60d189fe0a32ff6c606a85575fd26de8893 100644
--- a/chrome/browser/android/offline_pages/downloads/resource_throttle.cc
+++ b/chrome/browser/android/offline_pages/downloads/resource_throttle.cc
@@ -47,8 +47,16 @@ ResourceThrottle::~ResourceThrottle() {
 
 void ResourceThrottle::WillProcessResponse(bool* defer) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+
+  if (request_->url_chain().empty())

[Dmitry Titov, 2017/04/25 07:03:01]

URLRequest is constructed with at least one URL, the chain is never empty.
I think this check can be safely omitted and instead of url_chain().back() it
can just fetch request_->url() in the next line.

[qinmin, 2017/04/25 18:52:45]

Done.

+    return;
+  GURL url = request_->url_chain().back();
+  if (!url.SchemeIsHTTPOrHTTPS())
+    return;
+
   std::string mime_type;
   request_->GetMimeType(&mime_type);
+
   if (CanDownloadAsOfflinePage(mime_type)) {

[David Trainor- moved to gerrit, 2017/04/25 03:31:16]

Would it be cleaner to bake that into CanDownloadAsOfflinePage?  e.g.

CanDownloadAsOfflinePage(url, mime_type)?

[Dmitry Titov, 2017/04/25 07:03:01]

+1, good suggestion.

[qinmin, 2017/04/25 18:52:45]

Done.

     const content::ResourceRequestInfo* info =
         content::ResourceRequestInfo::ForRequest(request_);