Add UMA for the content suggestions settings

chrome/android/java/src/org/chromium/chrome/browser/suggestions/ContentSuggestionsUma.java

+// 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.
+
+package org.chromium.chrome.browser.suggestions;
+
+import android.annotation.IntDef;
+
+import org.chromium.base.metrics.RecordHistogram;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Centralises the UMA recording related to content suggestions.
+ * TODO(https://crbug.com/707767): Move relevant methods from SnippetsBridge and NewTabPageUma here.
+ */
+public final class ContentSuggestionsUma {
+    private ContentSuggestionsUma() {}
+
+    private static final String REMOTE_SUGGESTIONS_PREF_TOGGLE_HISTOGRAM_NAME = "";

[Michael van Ouwerkerk, 2017/04/04 14:09:47]

No name?

[dgn, 2017/04/04 19:02:54]

Done.

+
+    @IntDef({PREFERENCE_TOGGLE_ON_TO_ON, PREFERENCE_TOGGLE_ON_TO_OFF, PREFERENCE_TOGGLE_OFF_TO_ON,
+            PREFERENCE_TOGGLE_OFF_TO_OFF})
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface PreferenceToggle {}
+    public static final int PREFERENCE_TOGGLE_ON_TO_ON = 0;
+    public static final int PREFERENCE_TOGGLE_ON_TO_OFF = 1;
+    public static final int PREFERENCE_TOGGLE_OFF_TO_ON = 2;
+    public static final int PREFERENCE_TOGGLE_OFF_TO_OFF = 3;
+    private static final int PREFERENCE_TOGGLE_INDEX_BOUNDARY = 4;
+
+    public static void remoteSuggestionsPreferencesUIAction(@PreferenceToggle int action) {

[Michael van Ouwerkerk, 2017/04/04 14:09:47]

maybe rename to something like recordPreferencesChange or
recordPreferencesToggle so that:
* Avoid UI acronym and capitalization discussions
* Indicate this records something
* Do not imply this records an action, it's a histogram

[dgn, 2017/04/04 19:02:54]

Ack

+        RecordHistogram.recordEnumeratedHistogram(REMOTE_SUGGESTIONS_PREF_TOGGLE_HISTOGRAM_NAME,
+                action, PREFERENCE_TOGGLE_INDEX_BOUNDARY);
+    }
+}