PlzNavigate: Invoke didStartProvisionalLoad() when the renderer initiates a navigation in startLoad(

chrome/renderer/net/net_error_helper.cc

Index: chrome/renderer/net/net_error_helper.cc
diff --git a/chrome/renderer/net/net_error_helper.cc b/chrome/renderer/net/net_error_helper.cc
index 1c3d935d64b2ba5825f33e89f7510f5eea9962ea..e8ee1d95d9c6ee094e121db7dcc8ddc2f5764041 100644
--- a/chrome/renderer/net/net_error_helper.cc
+++ b/chrome/renderer/net/net_error_helper.cc
@@ -66,9 +66,9 @@ namespace {
 // suggestions.  If it takes too long, just use the local error page.
 const int kNavigationCorrectionFetchTimeoutSec = 3;
 
-NetErrorHelperCore::PageType GetLoadingPageType(RenderFrame* render_frame) {
-  blink::WebFrame* web_frame = render_frame->GetWebFrame();
-  GURL url = web_frame->provisionalDataSource()->getRequest().url();
+NetErrorHelperCore::PageType GetLoadingPageType(
+    blink::WebDataSource* data_source) {
+  GURL url = data_source->getRequest().url();
   if (!url.is_valid() || url.spec() != kUnreachableWebDataURL)
     return NetErrorHelperCore::NON_ERROR_PAGE;
   return NetErrorHelperCore::ERROR_PAGE;
@@ -118,9 +118,10 @@ void NetErrorHelper::TrackClick(int tracking_id) {
   core_->TrackClick(tracking_id);
 }
 
-void NetErrorHelper::DidStartProvisionalLoad() {
+void NetErrorHelper::DidStartProvisionalLoad(
+    blink::WebDataSource* data_source) {
   core_->OnStartLoad(GetFrameType(render_frame()),
-                     GetLoadingPageType(render_frame()));
+                     GetLoadingPageType(data_source));
 }
 
 void NetErrorHelper::DidCommitProvisionalLoad(bool is_new_navigation,