Move browsing data counters helper functions to an 'utils' file.

chrome/browser/browsing_data/browsing_data_counter_utils.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_BROWSING_DATA_BROWSING_DATA_COUNTER_UTILS_H_
+#define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_COUNTER_UTILS_H_
+
+#include "chrome/browser/browsing_data/browsing_data_counter.h"
+
+namespace browsing_data {

[Bernhard Bauer, 2015/12/16 13:35:32]

I think the general guideline now is against using namespaces in top-level
chrome/ code. If anything, the namespace should be named after the file name,
i.e. browsing_data_counter_utils? That does seem a bit unwieldy, but maybe you
can import these with `using` where they are used.

[msramek, 2016/01/05 16:22:50]

I removed the namespace; it's true that other files in this directory don't use
one either.

I found this thread 
https://groups.google.com/a/chromium.org/forum/#!searchin/chromium-dev/namesp...
on chromium-dev, which is probably what you're referring to. But the style guide
itself pretty much encourages using namespaces everywhere.

+
+// Whether the browsing data counters experiment is enabled.
+bool AreCountersEnabled();
+
+// Constructs the text to be displayed by a counter from the given |result|.
+base::string16 GetCounterTextFromResult(

[Bernhard Bauer, 2015/12/16 13:35:32]

#include "base/string16.h"

[msramek, 2016/01/05 16:22:50]

Done.

+    const BrowsingDataCounter::Result* result);
+
+// Creates a new instance of BrowsingDataCounter that is counting the data
+// related to a given deletion preference |pref_name|.
+BrowsingDataCounter* CreateCounterForPreference(std::string pref_name);
+
+}  // namespace browsing_data
+
+#endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_COUNTER_UTILS_H_