[Autofill] Add upstreaming UKM

components/autofill/core/browser/autofill_ukm.h

Index: components/autofill/core/browser/autofill_ukm.h
diff --git a/components/autofill/core/browser/autofill_ukm.h b/components/autofill/core/browser/autofill_ukm.h
new file mode 100644
index 0000000000000000000000000000000000000000..e3dc42c267aa7d8a99101105fe625ea740ab4d74
--- /dev/null
+++ b/components/autofill/core/browser/autofill_ukm.h
@@ -0,0 +1,48 @@
+// Copyright 2017 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 COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_UKM_H_
+#define COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_UKM_H_
+
+#include "base/macros.h"
+#include "components/autofill/core/browser/autofill_metrics.h"
+
+class GURL;
+
+namespace ukm {
+class UkmService;
+}  // namespace ukm
+
+namespace autofill {
+
+// A class to log Autofill related Url Keyed Metrics.

[Mathieu, 2017/03/08 22:33:49]

Mention why it exists: sometimes the URL is not in the same codepath as the
metric being logged. 

+class AutofillUkm {

[Mathieu, 2017/03/08 22:33:49]

Would rename this AutofillUkmSession

+ public:
+  AutofillUkm(ukm::UkmService* ukm_service);
+  ~AutofillUkm();
+
+  // Sets the URL to be used when logging the next card upload decision metric.
+  void SetCardUploadDecisionMetricUrl(const GURL& url);
+
+  // Logs the card upload decision metric based on the set URL. Does nothing if
+  // no URL is set. Resets the URL after the log.
+  void LogCardUploadDecisionMetric(
+      AutofillMetrics::CardUploadDecisionMetric upload_decision);
+
+ private:
+  // Returns whether a UKM should be logged for the specified |url|.
+  bool ShouldLog(const GURL& url);
+
+  // The URL to use for the next card upload decision metric log.
+  std::unique_ptr<GURL> card_upload_decision_url_;
+
+  // Used to log URL-keyed metrics. This pointer will outlive |this|.
+  ukm::UkmService* ukm_service_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(AutofillUkm);

[Mathieu, 2017/03/08 22:33:49]

curious, why not DISALLOW_COPY_AND_ASSIGN?

+};
+
+}  // namespace autofill
+
+#endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_UKM_H_