[Offline Pages] Allow BackgroundLoader to track network bytes using prerenderer hook-in.

chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc

Index: chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
diff --git a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
index 893828fc193c2b52f6216f75797e34c6eea70248..0ddcbdb3c45b0666edd2a90a5135fac4c72cf7b5 100644
--- a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
+++ b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
@@ -107,6 +107,7 @@
 
 #if defined(OS_ANDROID)
 #include "chrome/browser/android/download/intercept_download_resource_throttle.h"
+#include "chrome/browser/android/offline_pages/background_loader_offliner.h"
 #include "chrome/browser/android/offline_pages/downloads/resource_throttle.h"
 #include "chrome/browser/loader/data_reduction_proxy_resource_throttle_android.h"
 #include "components/navigation_interception/intercept_navigation_delegate.h"
@@ -372,8 +373,16 @@ void NotifyUIThreadOfRequestComplete(
     LogMainFrameMetricsOnUIThread(url, net_error, request_loading_time,
                                   web_contents);
   }
-  if (!was_cached)
+  if (!was_cached) {
     UpdatePrerenderNetworkBytesCallback(web_contents, total_received_bytes);
+#if defined(OS_ANDROID)
+    offline_pages::BackgroundLoaderOffliner* background_loader =
+        offline_pages::BackgroundLoaderOffliner::FromWebContents(web_contents);
+
+    if (background_loader)
+      background_loader->OnNetworkBytesChanged(total_received_bytes);
+#endif  // OS_ANDROID
+  }
   page_load_metrics::MetricsWebContentsObserver* metrics_observer =
       page_load_metrics::MetricsWebContentsObserver::FromWebContents(
           web_contents);