Function to count dialog box creations.

chrome/browser/ui/views/dialog_uma/dialog_uma.h

Index: chrome/browser/ui/views/dialog_uma/dialog_uma.h
diff --git a/chrome/browser/ui/views/dialog_uma/dialog_uma.h b/chrome/browser/ui/views/dialog_uma/dialog_uma.h
new file mode 100644
index 0000000000000000000000000000000000000000..43a54b6543b06f6842acdbfb7669d49605091100
--- /dev/null
+++ b/chrome/browser/ui/views/dialog_uma/dialog_uma.h
@@ -0,0 +1,17 @@
+// 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 CHROME_BROWSER_UI_VIEWS_DIALOG_UMA_DIALOG_UMA_H_

[msw, 2017/04/05 00:26:54]

A couple questions:
(1) Why is this specific to views? (seems viable for Mac/Android/iOS too)
(2) Why create the dialog_uma subdir? (seems unnecessary for two files)

[pdyson, 2017/04/05 03:43:24]

(1) This is to enable DPM (decisions per thousand) to be measured. DPM
already has good coverage for InfoBars on Android and iOS using UMA
metric InfoBar.Shown. This CL is to start adding coverage for Dialog
Boxes on Windows/Linux (and Mac when it moves to views). So I think
that makes Views the appropriate place, but I'm quite new to the Chrome
code base.

(2) I'm open to ideas on where this should go. How about
chrome/browser/ui/views/dialog_uma.h? 

[msw, 2017/04/05 04:32:12]

Is there a reason that this shouldn't support Cocoa in the interim on Mac?
That would be better, if it should be views-specific. Or I'd suggest:
chrome/browser/ui/browser_dialogs.h (and a new *.cc)

+#define CHROME_BROWSER_UI_VIEWS_DIALOG_UMA_DIALOG_UMA_H_
+
+// Values used in the Dialog.Creation UMA metric. Each value represents a
+// different type of dialog box.
+// These values are written to logs. New enum values can be added, but existing
+// enums must never be renumbered or deleted and reused.
+enum class DialogIdentifier { UNKNOWN = 0, TRANSLATE = 1, MAX_VALUE };
+
+// Record an UMA metric counting the creation of a dialog box of this type.
+void RecordDialogCreation(DialogIdentifier identifier);
+
+#endif  // CHROME_BROWSER_UI_VIEWS_DIALOG_UMA_DIALOG_UMA_H_