Various cleaups for AMP page load metrics.

chrome/browser/page_load_metrics/page_load_metrics_util.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_UTIL_H_
 #define CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_UTIL_H_
 
 #include "base/metrics/histogram_macros.h"
 #include "base/optional.h"
 #include "base/time/time.h"
@@ skipping 113 matching lines @@
 base::Optional<base::TimeDelta> OptionalMin(
     const base::Optional<base::TimeDelta>& a,
     const base::Optional<base::TimeDelta>& b);
 
 // Whether the given loading behavior was observed in any frame (either the main
 // frame or a subframe).
 bool DidObserveLoadingBehaviorInAnyFrame(
     const page_load_metrics::PageLoadExtraInfo& info,
     blink::WebLoadingBehaviorFlag behavior);
 
+// Whether the given url has a google hostname.
+bool IsGoogleHostname(const GURL& url);
+
+// If the given hostname is a google hostname, returns the portion of the
+// hostname before the google hostname. Otherwise, returns an unset optional
+// value.
+//
+// For example:
+//   https://example.com/foo => returns an unset optional value
+//   https://google.com/foo => returns ''
+//   https://www.google.com/foo => returns 'www'
+//   https://news.google.com/foo => returns 'news'
+//   https://a.b.c.google.com/foo => returns 'a.b.c'
+base::Optional<std::string> GetGoogleHostnamePrefix(const GURL& url);
+
 }  // namespace page_load_metrics
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_UTIL_H_