PlzNavigate: implement CommitNavigation on the browser side

content/browser/frame_host/navigation_request_info.h

Index: content/browser/frame_host/navigation_request_info.h
diff --git a/content/browser/frame_host/navigation_request_info.h b/content/browser/frame_host/navigation_request_info.h
index cc6d5a70f131f7e8118a2887a07627634002f747..1800531b9acc9eb1b1d55e128a0c8e181e12019c 100644
--- a/content/browser/frame_host/navigation_request_info.h
+++ b/content/browser/frame_host/navigation_request_info.h
@@ -18,7 +18,8 @@ namespace content {
 // ResourceDispatcherHost. It is initialized on the UI thread, and then passed
 // to the IO thread by a NavigationRequest object.
 struct NavigationRequestInfo {
-  NavigationRequestInfo(const FrameHostMsg_BeginNavigation_Params& params);
+  explicit NavigationRequestInfo(
+      const FrameHostMsg_BeginNavigation_Params& params);
 
   const FrameHostMsg_BeginNavigation_Params navigation_params;