Added merge session request throttle for XHR requests

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc

Index: chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
diff --git a/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc b/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
index 83936591b948e45115155f8325681eaafe2cfd28..9eb0e0e6e917a0abf16108493b8e3237dcdbaf37 100644
--- a/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
+++ b/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
@@ -269,7 +269,8 @@ void ChromeResourceDispatcherHostDelegate::RequestBeginning(
   }
 
 #if defined(OS_CHROMEOS)
-  if (resource_type == ResourceType::MAIN_FRAME) {
+  if (resource_type == ResourceType::MAIN_FRAME ||
+      resource_type == ResourceType::XHR) {
     // We check offline first, then check safe browsing so that we still can
     // block unsafe site after we remove offline page.
     throttles->push_back(new OfflineResourceThrottle(request,
@@ -279,7 +280,7 @@ void ChromeResourceDispatcherHostDelegate::RequestBeginning(
     // progress while we are attempting to load a google property.
     if (!MergeSessionThrottle::AreAllSessionMergedAlready() &&
         request->url().SchemeIsHTTPOrHTTPS()) {
-      throttles->push_back(new MergeSessionThrottle(request));
+      throttles->push_back(new MergeSessionThrottle(request, resource_type));
     }
   }
 #endif