Clean up descriptions and add metrics for the Data Saver UI

chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionMainMenuFooter.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionMainMenuFooter.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionMainMenuFooter.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionMainMenuFooter.java
index 62e8031c20b550e0440f9f9e8c93ad983d7df641..f77c23d3ee207a3c765a3a7b8c1140c71a583a1d 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionMainMenuFooter.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionMainMenuFooter.java
@@ -46,6 +46,9 @@ public class DataReductionMainMenuFooter extends FrameLayout implements View.OnC
         TextView itemSummary = (TextView) findViewById(R.id.menu_item_summary);
 
         if (DataReductionProxySettings.getInstance().isDataReductionProxyEnabled()) {
+            DataReductionProxyUma.dataReductionProxyUIAction(
+                    DataReductionProxyUma.ACTION_MAIN_MENU_DISPLAYED_ON);
+
             String dataSaved = Formatter.formatShortFileSize(getContext(),
                     DataReductionProxySettings.getInstance()
                             .getContentLengthSavedInHistorySummary());
@@ -65,6 +68,9 @@ public class DataReductionMainMenuFooter extends FrameLayout implements View.OnC
                     getContext().getResources(), R.color.light_active_color);
             itemText.setTextColor(lightActiveColor);
         } else {
+            DataReductionProxyUma.dataReductionProxyUIAction(
+                    DataReductionProxyUma.ACTION_MAIN_MENU_DISPLAYED_OFF);
+
             itemText.setText(R.string.data_reduction_title);
             itemSummary.setText(R.string.text_off);