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

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/offline_pages/downloads/resource_throttle.h"
 
 #include "base/logging.h"
 #include "chrome/browser/android/offline_pages/offline_page_utils.h"
 #include "components/offline_pages/core/client_namespace_constants.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 29 matching lines @@
     : request_(request) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 }
 
 ResourceThrottle::~ResourceThrottle() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 }
 
 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_);
     if (!info)
       return;
     content::BrowserThread::PostTask(
         content::BrowserThread::UI, FROM_HERE,
         base::Bind(&WillStartOfflineRequestOnUIThread, request_->url(),
                    info->GetWebContentsGetterForRequest()));
     Cancel();
   }
 }
 
 const char* ResourceThrottle::GetNameForLogging() const {
   return "offline_pages::downloads::ResourceThrottle";
 }
 
 }  // namespace downloads
 }  // namespace offline_pages