Add additional metrics for main intent behaviors.

chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java

 // 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.
 
 package org.chromium.chrome.browser;
 
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.ActivityManager;
@@ skipping 733 matching lines @@
             return false;
         }
 
         if (mLayoutManager != null && mLayoutManager.overviewVisible() && !isTablet()) {
             mLayoutManager.hideOverview(false);
         }
 
         // In cases where the tab model is initialized, attempt to reuse an existing NTP if
         // available before attempting to create a new one.
         TabModel normalTabModel = getTabModelSelector().getModel(false);
+        Tab ntpToRefocus = null;
         for (int i = 0; i < normalTabModel.getCount(); i++) {
             Tab tab = normalTabModel.getTabAt(i);
 
             if (NewTabPage.isNTPUrl(tab.getUrl()) && !tab.canGoBack() && !tab.canGoForward()) {
+                // If the currently selected tab is an NTP, then take no action.
                 if (getActivityTab().equals(tab)) return true;
-
-                normalTabModel.moveTab(tab.getId(), normalTabModel.getCount());
-                normalTabModel.setIndex(
-                        TabModelUtils.getTabIndexById(normalTabModel, tab.getId()),
-                        TabSelectionType.FROM_USER);
-                return true;
+                ntpToRefocus = tab;
+                break;
             }
         }
 
-        getTabCreator(false).launchUrl(UrlConstants.NTP_URL, TabLaunchType.FROM_EXTERNAL_APP);
+        if (ntpToRefocus != null) {
+            normalTabModel.moveTab(ntpToRefocus.getId(), normalTabModel.getCount());
+            normalTabModel.setIndex(
+                    TabModelUtils.getTabIndexById(normalTabModel, ntpToRefocus.getId()),
+                    TabSelectionType.FROM_USER);
+        } else {
+            getTabCreator(false).launchUrl(UrlConstants.NTP_URL, TabLaunchType.FROM_EXTERNAL_APP);
+        }
+        RecordUserAction.record("MobileStartup.MainIntent.NTPCreatedDueToInactivity");
         return true;
     }
 
     @Override
     public void initializeState() {
         // This method goes through 3 steps:
         // 1. Load the saved tab state (but don't start restoring the tabs yet).
         // 2. Process the Intent that this activity received and if that should result in any
         //    new tabs, create them.  This is done after step 1 so that the new tab gets
         //    created after previous tab state was restored.
@@ skipping 1163 matching lines @@
 
         ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
         for (AppTask task : manager.getAppTasks()) {
             RecentTaskInfo info = DocumentUtils.getTaskInfoFromTask(task);
             if (info == null) continue;
             if (info.id == sMergedInstanceTaskId) return true;
         }
         return false;
     }
 }