Add more Rappor metrics

chrome/browser/rappor/sampling.h

Index: chrome/browser/rappor/sampling.h
diff --git a/chrome/browser/rappor/sampling.h b/chrome/browser/rappor/sampling.h
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+++ b/chrome/browser/rappor/sampling.h
@@ -0,0 +1,26 @@
+// Copyright 2014 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_RAPPOR_SAMPLING_H_
+#define CHROME_BROWSER_RAPPOR_SAMPLING_H_
+
+#include <string>
+
+class GURL;
+
+namespace rappor {
+
+// Record the ETLD+1 of a url to a Rappor metric.

[Peter Kasting, 2014/06/09 00:51:14]

Nit: Record -> Records (2 places)

I would probably say "domain and registry" instead of "ETLD+1" to match the
function name and the registry-controlled domain service terminology.  If you
think this is super-unclear, you could perhaps add a parenthetical "(a.k.a. the
eTLD+1, "foo.co.uk")" or refer the reader to the RCDS comments for a definition.

[Steven Holte, 2014/06/09 17:54:29]

Done.

+// If the service is NULL, this becomes a no-op.

[Peter Kasting, 2014/06/09 00:51:14]

Tiny nit: Minor, but I think this might be a little clearer: "If the Rappor
service is NULL, this call does nothing."  Maybe say when that service might be
NULL if any callers would actually care about such a thing.

[Steven Holte, 2014/06/09 17:54:29]

Done.

+void SampleDomainAndRegistryFromGURL(const std::string& metric,
+                                     const GURL& gurl);
+
+// Record the ETLD+1 of a host to a Rappor metric.
+// If the service is NULL, this becomes a no-op.
+void SampleDomainAndRegistryFromHost(const std::string& metric,
+                                     const std::string& host);
+
+}  // namespace rappor
+
+#endif  // CHROME_BROWSER_RAPPOR_SAMPLING_H_