Prepare ClearBrowsingDataDialogFragment for browsing data counters.

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 "base/strings/string16.h"
 #include "chrome/browser/browsing_data/browsing_data_counter.h"
 
 // Whether the browsing data counters experiment is enabled.

[newt (away), 2016/01/12 18:55:27]

Tangential comment: Perhaps these static methods should live inside a namespace.
Without a namespace, it's quite difficult to figure out where, say,
"AreCountersEnabled()" is defined when reading other code that uses these
functions. This could be a follow-up CL if you plan to change this.

See
https://google.github.io/styleguide/cppguide.html#Nonmember,_Static_Member,_a...

[msramek, 2016/01/13 15:27:53]

I originally did have a namespace :-) See the code review:
https://codereview.chromium.org/1527653004/diff/20001/chrome/browser/browsing...

[newt (away), 2016/01/13 20:01:49]

Ah, well I respectfully submit my opposing opinion :)  I think this case is a
bit different because the methods aren't enclosed in a class. Anyway, the
decision is up to you.

[msramek, 2016/01/14 15:45:43]

Very well :) Then I think it's best if we go with the other option from the
linked review, and that is to define a very narrow namespace that matches the
file name. That is roughly equivalent to encapsulating them into a static class,
but AFAIK, the latter is a Java approach, the former is more acceptable in C++.

I created a follow-up CL https://codereview.chromium.org/1581173004.

 bool AreCountersEnabled();
 
 // Constructs the text to be displayed by a counter from the given |result|.
 base::string16 GetCounterTextFromResult(
     const BrowsingDataCounter::Result* result);
 
+// Browsing data types as seen in the Android UI.
+//
+// A Java counterpart will be generated for this enum.
+// GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser
+enum ClankBrowsingDataType {

[newt (away), 2016/01/12 18:55:26]

Don't use the word "clank" in code. How about just "BrowsingDataType" (or
"BrowsingDataTypeAndroid" if this isn't applicable to other platforms)?

[msramek, 2016/01/13 15:27:53]

Done. Yes, I wasn't sure about that, but I found some occurrences of "Clank" in
the code, so I assumed it was OK.

I'll remove the "Android" part altogether to reference that this should be
reused on Desktop and later iOS as well (see the comment in
pref_service_bridge.cc).

+  HISTORY,
+  CACHE,
+  COOKIES,
+  PASSWORDS,
+  FORM_DATA,
+  BOOKMARKS,
+  NUM_TYPES = BOOKMARKS

[newt (away), 2016/01/12 18:55:26]

remove " = BOOKMARKS". In this case, BOOKMARKS will be 5, and NUM_TYPES should
be 6.

[msramek, 2016/01/13 15:27:53]

Ah, of course.

+};
+
+// Copies the name of the deletion preference corresponding to the given
+// |data_type| to |out_pref|. Returns false if no such preference exists.
+bool GetDeletionPreferenceFromDataType(
+    ClankBrowsingDataType data_type, std::string* out_pref);
+
 // 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);
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_COUNTER_UTILS_H_