Plumb initiator out of Blink.

content/shell/test_runner/web_frame_test_proxy.h

Index: content/shell/test_runner/web_frame_test_proxy.h
diff --git a/content/shell/test_runner/web_frame_test_proxy.h b/content/shell/test_runner/web_frame_test_proxy.h
index 6a3db31c72cfce443c60ddff9c0d06c0b8e3718f..671b1dad850deb358fbe65e54382fa216f54168e 100644
--- a/content/shell/test_runner/web_frame_test_proxy.h
+++ b/content/shell/test_runner/web_frame_test_proxy.h
@@ -96,10 +96,12 @@ class WebFrameTestProxy : public Base, public WebFrameTestProxyBase {
                             replaces_current_history_item);
   }
 
-  void didStartProvisionalLoad(blink::WebDataSource* data_source,
+  void didStartProvisionalLoad(blink::WebLocalFrame* initiator_frame,
+                               blink::WebDataSource* data_source,
                                blink::WebURLRequest& request) override {
-    test_client()->didStartProvisionalLoad(data_source, request);
-    Base::didStartProvisionalLoad(data_source, request);
+    test_client()->didStartProvisionalLoad(initiator_frame, data_source,
+                                           request);
+    Base::didStartProvisionalLoad(initiator_frame, data_source, request);
   }
 
   void didReceiveServerRedirectForProvisionalLoad(