Introduce moderate binding

chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeMobileApplication.java

Index: chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeMobileApplication.java
diff --git a/chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeMobileApplication.java b/chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeMobileApplication.java
index 083cee4cb1f92758af07922bc1282fa64426d363..51b7b0ea320601703497399a614bface87918dd5 100644
--- a/chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeMobileApplication.java
+++ b/chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeMobileApplication.java
@@ -24,6 +24,7 @@ import org.chromium.base.ResourceExtractor;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.SuppressFBWarnings;
+import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.browser.accessibility.FontSizePrefs;
 import org.chromium.chrome.browser.banners.AppBannerManager;
 import org.chromium.chrome.browser.banners.AppDetailsDelegate;
@@ -59,15 +60,18 @@ import org.chromium.chrome.browser.smartcard.EmptyPKCS11AuthenticationManager;
 import org.chromium.chrome.browser.smartcard.PKCS11AuthenticationManager;
 import org.chromium.chrome.browser.sync.SyncController;
 import org.chromium.chrome.browser.tab.AuthenticatorNavigationInterceptor;
+import org.chromium.chrome.browser.tabmodel.TabModelSelector;
 import org.chromium.chrome.browser.tabmodel.document.ActivityDelegate;
 import org.chromium.chrome.browser.tabmodel.document.DocumentTabModelSelector;
 import org.chromium.chrome.browser.tabmodel.document.StorageDelegate;
+import org.chromium.chrome.browser.util.FeatureUtilities;
 import org.chromium.content.browser.ChildProcessLauncher;
 import org.chromium.content.browser.ContentViewStatics;
 import org.chromium.content.browser.DownloadController;
 import org.chromium.printing.PrintingController;
 import org.chromium.ui.UiUtils;
 
+import java.lang.ref.WeakReference;
 import java.util.Locale;
 
 /**
@@ -396,6 +400,27 @@ public class ChromeMobileApplication extends ChromiumApplication {
 
         ChildProcessLauncher.onSentToBackground();
         IntentHandler.clearPendingReferrer();
+
+        if (FeatureUtilities.isDocumentMode(this)) {
+            if (sDocumentTabModelSelector != null) {
+                RecordHistogram.recordCountHistogram("Tab.TotalTabCountBeforeLeavingApp",
+                        sDocumentTabModelSelector.getTotalTabCount());
+            }
+        } else {
+            int totalTabCount = 0;
+            for (WeakReference<Activity> reference : ApplicationStatus.getRunningActivities()) {
+                Activity activity = reference.get();
+                if (activity == null) continue;

[Alexei Svitkine (slow), 2015/06/19 17:17:56]

Nit: Not necessarily, since the check below will be false if activity is null:

http://stackoverflow.com/questions/2950319/is-null-check-needed-before-callin...

[Jaekyun Seok (inactive), 2015/06/22 01:48:57]

Done.

+                if (activity instanceof ChromeActivity) {
+                    TabModelSelector tabModelSelector =
+                            ((ChromeActivity) activity).getTabModelSelector();
+                    totalTabCount +=
+                            tabModelSelector == null ? 0 : tabModelSelector.getTotalTabCount();

[Alexei Svitkine (slow), 2015/06/19 17:17:56]

Nit: I think it's cleaner for this to be a regular if.

if (tabModelSelector != null)
  totalTabCount += tabModelSelector.getTotalTabCount();

[Jaekyun Seok (inactive), 2015/06/22 01:48:56]

Done.

+                }
+            }
+            RecordHistogram.recordCountHistogram(
+                    "Tab.TotalTabCountBeforeLeavingApp", totalTabCount);
+        }
     }
 
     /**