Record how often we end up in Chrome from external navigations.

chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.java

Index: chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.java
index 1f3e92d29ee40979c3c4066c8b3e75b407ff8e2e..b1b4a51182be4679ffdd2f44f7a80b2390177260 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.java
@@ -37,6 +37,7 @@ import org.chromium.chrome.browser.ChromeTabbedActivity2;
 import org.chromium.chrome.browser.IntentHandler;
 import org.chromium.chrome.browser.document.ChromeLauncherActivity;
 import org.chromium.chrome.browser.externalnav.ExternalNavigationHandler.OverrideUrlLoadingResult;
+import org.chromium.chrome.browser.rappor.RapporServiceBridge;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.util.FeatureUtilities;
 import org.chromium.chrome.browser.util.UrlUtilities;
@@ -47,6 +48,7 @@ import org.chromium.ui.base.WindowAndroid;
 import org.chromium.ui.base.WindowAndroid.PermissionCallback;
 import org.chromium.webapk.lib.client.WebApkValidator;
 
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -239,13 +241,14 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
 
     @Override
     public int countSpecializedHandlers(List<ResolveInfo> infos) {
-        return countSpecializedHandlersWithFilter(infos, null);
+        return getSpecializedHandlersWithFilter(infos, null).size();
     }
 
-    static int countSpecializedHandlersWithFilter(
+    static ArrayList<String> getSpecializedHandlersWithFilter(
             List<ResolveInfo> infos, String filterPackageName) {
+        ArrayList<String> result = new ArrayList<String>();
         if (infos == null) {
-            return 0;
+            return result;
         }
 
         int count = 0;
@@ -266,9 +269,9 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
                 continue;
             }
 
-            ++count;
+            result.add(info.activityInfo.packageName);
         }
-        return count;
+        return result;
     }
 
     /**
@@ -285,7 +288,7 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
         try {
             List<ResolveInfo> handlers = context.getPackageManager().queryIntentActivities(
                     intent, PackageManager.GET_RESOLVED_FILTER);
-            return countSpecializedHandlersWithFilter(handlers, packageName) > 0;
+            return getSpecializedHandlersWithFilter(handlers, packageName).size() > 0;
         } catch (RuntimeException e) {
             logTransactionTooLargeOrRethrow(e, intent);
         }
@@ -312,6 +315,7 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
             Context context = getAvailableContext();
             if (!(context instanceof Activity)) intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
             context.startActivity(intent);
+            recordExternalNavigationPackageName(intent);
         } catch (RuntimeException e) {
             logTransactionTooLargeOrRethrow(e, intent);
         }
@@ -319,6 +323,7 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
 
     @Override
     public boolean startActivityIfNeeded(Intent intent) {
+        boolean result;

[gone, 2016/06/29 16:30:44]

activityWasLaunched?  result isn't too meaningful without looking up the API
documentation.

         // Only touches disk on Kitkat. See http://crbug.com/617725 for more context.
         StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
         StrictMode.allowThreadDiskReads();
@@ -326,10 +331,12 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
             forcePdfViewerAsIntentHandlerIfNeeded(mApplicationContext, intent);
             Context context = getAvailableContext();
             if (context instanceof Activity) {
-                return ((Activity) context).startActivityIfNeeded(intent, -1);
+                result = ((Activity) context).startActivityIfNeeded(intent, -1);
             } else {
-                return false;
+                result = false;
             }
+            if (result) recordExternalNavigationPackageName(intent);
+            return result;
         } catch (RuntimeException e) {
             logTransactionTooLargeOrRethrow(e, intent);
             return false;
@@ -338,6 +345,16 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
         }
     }
 
+    private void recordExternalNavigationPackageName(Intent intent) {
+        List<String> packages = intent.getStringArrayListExtra(
+                IntentHandler.EXTRA_EXTERNAL_NAV_PACKAGES);
+        if (packages != null) {

[gone, 2016/06/29 16:30:44]

early return instead to avoid the extra indentation?

+            for (String name : packages) {
+                RapporServiceBridge.sampleString("Android.ExternalNavigationOption", name);
+            }
+        }
+    }
+
     @Override
     public void startIncognitoIntent(final Intent intent, final String referrerUrl,
             final String fallbackUrl, final Tab tab, final boolean needsToCloseTab) {
@@ -522,4 +539,10 @@ public class ExternalNavigationDelegateImpl implements ExternalNavigationDelegat
 
         return PDF_EXTENSION.equals(fileExtension);
     }
+
+    @Override
+    public void maybeSetAppHandlers(Intent intent, List<ResolveInfo> infos) {

[gone, 2016/06/29 16:30:44]

maybeRecordAppHandlersInIntent?

+        intent.putExtra(IntentHandler.EXTRA_EXTERNAL_NAV_PACKAGES,
+                getSpecializedHandlersWithFilter(infos, null));
+    }
 }