Call CSD whitelist checking on UI thread and record UMA

components/safe_browsing/password_protection/password_protection_service.h

Index: components/safe_browsing/password_protection/password_protection_service.h
diff --git a/components/safe_browsing/password_protection/password_protection_service.h b/components/safe_browsing/password_protection/password_protection_service.h
new file mode 100644
index 0000000000000000000000000000000000000000..ddbe354aa498ec38a9f75019942da9ac86af21ba
--- /dev/null
+++ b/components/safe_browsing/password_protection/password_protection_service.h
@@ -0,0 +1,43 @@
+// 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_SAFE_BROWSING_PASSWORD_PROTECTION_PASSWORD_PROTECTION_SERVICE_H_
+#define COMPONENTS_SAFE_BROWSING_PASSWORD_PROTECTION_PASSWORD_PROTECTION_SERVICE_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+
+class GURL;
+
+namespace safe_browsing {
+
+class SafeBrowsingDatabaseManager;
+
+class PasswordProtectionService
+    : public base::RefCountedThreadSafe<PasswordProtectionService> {
+ public:
+  PasswordProtectionService(
+      const scoped_refptr<SafeBrowsingDatabaseManager>& database_manager);
+
+  // Called on UI thread.
+  void RecordPasswordReuse(const GURL& main_frame_url);

[Nathan Parker, 2017/03/01 22:59:22]

Other args we may want, eventually:
* origins of the reused saved-password

[vakh (use Gerrit instead), 2017/03/01 23:25:19]

Same for this method... please add a comment explaining what it does, when to
call it, etc.

[Jialiu Lin, 2017/03/02 00:53:06]

Done.

[Jialiu Lin, 2017/03/02 00:53:06]

ack. It seems password_reuse_detection_manager itself already logged some UMA
for saved_passwords.
Do you have any metrics in mind? It can be easily added in the future anyway. 

[Nathan Parker, 2017/03/02 01:02:42]

nah, never mind -- we can add it later when we want this to trigger a ping
(since that value will go in the ping).

+
+ protected:
+  virtual ~PasswordProtectionService();
+  // Called on UI thread.

[vakh (use Gerrit instead), 2017/03/01 23:25:20]

This is a good place to describe when this function is called and what it is
expected to do.

[Jialiu Lin, 2017/03/02 00:53:06]

Done.

+  void OnMatchCsdWhiteListResult(bool match_whitelist);
+
+ private:
+  friend class base::RefCountedThreadSafe<PasswordProtectionService>;
+
+  scoped_refptr<SafeBrowsingDatabaseManager> database_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(PasswordProtectionService);
+};
+
+}  // namespace safe_browsing
+
+#endif  // COMPONENTS_SAFE_BROWSING_PASSWORD_PROTECTION_PASSWORD_PROTECTION_SERVICE_H_