Pass browser user agent to android DownloadManager if no override UA is present.

content/browser/android/download_controller_android_impl.cc

 // Copyright (c) 2012 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 "content/browser/android/download_controller_android_impl.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "content/browser/android/content_view_core_impl.h"
 #include "content/browser/android/deferred_download_observer.h"
 #include "content/browser/download/download_item_impl.h"
 #include "content/browser/download/download_manager_impl.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_url_parameters.h"
 #include "content/public/browser/global_request_id.h"
 #include "content/public/browser/resource_request_info.h"
+#include "content/public/common/content_client.h"
 #include "content/public/common/referrer.h"
 #include "jni/DownloadController_jni.h"
 #include "net/cookies/cookie_options.h"
 #include "net/cookies/cookie_store.h"
 #include "net/http/http_content_disposition.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_response_headers.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 
@@ skipping 391 matching lines @@
 DownloadControllerAndroidImpl::DownloadInfoAndroid::DownloadInfoAndroid(
     net::URLRequest* request)
     : has_user_gesture(false) {
   request->GetResponseHeaderByName("content-disposition", &content_disposition);
 
   if (request->response_headers())
     request->response_headers()->GetMimeType(&original_mime_type);
 
   request->extra_request_headers().GetHeader(
       net::HttpRequestHeaders::kUserAgent, &user_agent);
+  if (user_agent.empty())
+    user_agent = GetContentClient()->GetUserAgent();
   GURL referer_url(request->referrer());
   if (referer_url.is_valid())
     referer = referer_url.spec();
   if (!request->url_chain().empty()) {
     original_url = request->url_chain().front();
     url = request->url_chain().back();
   }
 
   const content::ResourceRequestInfo* info =
       content::ResourceRequestInfo::ForRequest(request);
   if (info)
     has_user_gesture = info->HasUserGesture();
 }
 
 DownloadControllerAndroidImpl::DownloadInfoAndroid::~DownloadInfoAndroid() {}
 
 }  // namespace content