Set the right load flag for ResourceRequests on end-to-end reloads

https://chromiumcodereview.appspot.com/309693002/ introduces a cache policy in Blink indicating end-to-end reload. It translates to
the load flag net::LOAD_BYPASS_CACHE (instead of having blink set HTTP cache
headers "Pragma: no-cache" and "Cache-Control: no-cache".

BUG=376025

Review URL: https://codereview.chromium.org/308083009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274807 0039d316-1c4b-4281-b951-d872f2087c98

content/child/web_url_loader_impl.cc

@@ -342,6 +342,9 @@ void WebURLLoaderImpl::Context::Start(const WebURLRequest& request,
       // Required by LayoutTests/http/tests/misc/refresh-headers.php
       load_flags |= net::LOAD_VALIDATE_CACHE;
       break;
+    case WebURLRequest::ReloadBypassingCache:
+      load_flags |= net::LOAD_BYPASS_CACHE;
+      break;
     case WebURLRequest::ReturnCacheDataElseLoad:
       load_flags |= net::LOAD_PREFERRING_CACHE;
       break;

content/renderer/render_view_impl.cc

@@ -2033,6 +2033,7 @@ void RenderViewImpl::didCreateDataSource(WebLocalFrame* frame,
         document_state->set_load_type(DocumentState::LINK_LOAD_NORMAL);
         break;
       case WebURLRequest::ReloadIgnoringCacheData:  // reload.
+      case WebURLRequest::ReloadBypassingCache:  // end-to-end reload.
         document_state->set_load_type(DocumentState::LINK_LOAD_RELOAD);
         break;
       case WebURLRequest::ReturnCacheDataElseLoad:  // allow stale data.