PlzNavigate: identify same-page browser-initiated navigation.

net/base/url_util.cc

Index: net/base/url_util.cc
diff --git a/net/base/url_util.cc b/net/base/url_util.cc
index 062481fef392c9a9b103e152f86932addb997757..7958b33c1c28d27684ee609415c2fd94d5538faf 100644
--- a/net/base/url_util.cc
+++ b/net/base/url_util.cc
@@ -371,6 +371,16 @@ bool IsLocalhost(base::StringPiece host) {
   return false;
 }
 
+bool AreURLsInPageNavigation(const GURL& existing_url, const GURL& new_url) {
+  if (existing_url == new_url || !new_url.has_ref())
+    return false;
+
+  url::Replacements<char> replacements;
+  replacements.ClearRef();
+  return existing_url.ReplaceComponents(replacements) ==
+         new_url.ReplaceComponents(replacements);
+}
+
 GURL SimplifyUrlForRequest(const GURL& url) {
   DCHECK(url.is_valid());
   // Fast path to avoid re-canonicalization via ReplaceComponents.