Add UMA for the content suggestions settings

chrome/android/java/src/org/chromium/chrome/browser/preferences/ContentSuggestionsPreferences.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/ContentSuggestionsPreferences.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/ContentSuggestionsPreferences.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/ContentSuggestionsPreferences.java
index aa07ccc7da530071aff67eeecc81bd42fe6f0e01..4b2acd8c4472b684a7250d082cf8e315f2821f36 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/ContentSuggestionsPreferences.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/ContentSuggestionsPreferences.java
@@ -12,10 +12,12 @@
 import android.view.MenuInflater;
 import android.view.MenuItem;
 
+import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.help.HelpAndFeedback;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsBridge;
 import org.chromium.chrome.browser.profiles.Profile;
+import org.chromium.chrome.browser.suggestions.ContentSuggestionsUma;
 
 /**
  * Settings fragment that allows the user to configure content suggestions.
@@ -26,6 +28,7 @@
     private static final String PREF_CAVEATS = "suggestions_caveats";
     private static final String PREF_LEARN_MORE = "suggestions_learn_more";
 
+    private boolean mWasEnabledAtCreation;
     private boolean mIsEnabled;
 
     // Preferences, modified as the state of the screen changes.
@@ -42,9 +45,9 @@ public void onCreate(Bundle savedInstanceState) {
         setHasOptionsMenu(true);
         finishSwitchInitialisation();
 
-        boolean isEnabled = SnippetsBridge.isRemoteSuggestionsServiceEnabled();
-        mIsEnabled = !isEnabled; // Opposite so that we trigger side effects below.
-        updatePreferences(isEnabled);
+        mWasEnabledAtCreation = SnippetsBridge.isRemoteSuggestionsServiceEnabled();
+        mIsEnabled = !mWasEnabledAtCreation; // Opposite so that we trigger side effects below.
+        updatePreferences(mWasEnabledAtCreation);
     }
 
     @Override
@@ -67,6 +70,21 @@ public boolean onOptionsItemSelected(MenuItem item) {
         return false;
     }
 
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+
+        int statusChange;
+        if (mWasEnabledAtCreation) {
+            statusChange = mIsEnabled ? ContentSuggestionsUma.PREFERENCE_TOGGLE_ON_TO_ON
+                                      : ContentSuggestionsUma.PREFERENCE_TOGGLE_ON_TO_OFF;
+        } else {
+            statusChange = mIsEnabled ? ContentSuggestionsUma.PREFERENCE_TOGGLE_OFF_TO_ON
+                                      : ContentSuggestionsUma.PREFERENCE_TOGGLE_OFF_TO_OFF;
+        }
+        ContentSuggestionsUma.remoteSuggestionsPreferencesUIAction(statusChange);
+    }
+
     /**
      * Switches preference screens depending on whether the remote suggestions are enabled/disabled.
      * @param isEnabled Indicates whether the remote suggestions are enabled.
@@ -88,10 +106,12 @@ public void updatePreferences(boolean isEnabled) {
 
     private void setNotificationsPrefState(boolean visible) {
         if (visible) {
+            RecordUserAction.record("ContentSuggestions.RemoteSuggestionsPreferenceOn");
             if (findPreference(PREF_NOTIFICATIONS_SWITCH) != null) return;
             getPreferenceScreen().addPreference(mNotificationsSwitch);
             mNotificationsSwitch.setChecked(true); // TODO(dgn): initialise properly.
         } else {
+            RecordUserAction.record("ContentSuggestions.RemoteSuggestionsPreferenceOff");
             getPreferenceScreen().removePreference(mNotificationsSwitch);
         }
     }