PlzNavigate: add cancel navigation logic for uncommitted requests

content/browser/frame_host/navigation_before_commit_info.cc

Index: content/browser/frame_host/navigation_before_commit_info.cc
diff --git a/content/child/sync_load_response.cc b/content/browser/frame_host/navigation_before_commit_info.cc
similarity index 56%
copy from content/child/sync_load_response.cc
copy to content/browser/frame_host/navigation_before_commit_info.cc
index 163153aa23766cc3a0b71a8fa8e1730efdb7a464..f7ebb3c013e6831eea34af219d61c575de3f20c0 100644
--- a/content/child/sync_load_response.cc
+++ b/content/browser/frame_host/navigation_before_commit_info.cc
@@ -2,12 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/child/sync_load_response.h"
+#include "content/browser/frame_host/navigation_before_commit_info.h"
 
 namespace content {
 
-SyncLoadResponse::SyncLoadResponse() {}
-
-SyncLoadResponse::~SyncLoadResponse() {}
+NavigationBeforeCommitInfo::NavigationBeforeCommitInfo()
+    : navigation_request_id(0) {}
 
 }  // namespace content