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

chrome/android/javatests/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandlerTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandlerTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandlerTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandlerTest.java
index 4b92ddc6b93faf741134053dc1181254b5ca998b..affd9eaf34bb8e10d78b9c76b5376f774a43a389 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandlerTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandlerTest.java
@@ -1001,9 +1001,14 @@ public class ExternalNavigationHandlerTest extends InstrumentationTestCase {
         }
 
         @Override
-        public int countSpecializedHandlers(List<ResolveInfo> infos) {
+        public int countSpecializedHandlers(List<ResolveInfo> resolveInfos) {
+            return getSpecializedHandlers(resolveInfos).size();
+        }
+
+        private ArrayList<String> getSpecializedHandlers(List<ResolveInfo> infos) {
+            ArrayList<String> result = new ArrayList<>();
             if (infos == null) {
-                return 0;
+                return result;
             }
             int count = 0;
             for (ResolveInfo info : infos) {
@@ -1013,10 +1018,10 @@ public class ExternalNavigationHandlerTest extends InstrumentationTestCase {
                         || packageName.equals(NATIVE_APP_PACKAGE_NAME)
                         || packageName.equals(WEBAPK_PACKAGE_NAME)
                         || packageName.equals(WEBAPK_WITH_NATIVE_APP_PACKAGE_NAME)) {
-                    ++count;
+                    result.add(packageName);
                 }
             }
-            return count;
+            return result;
         }
 
         @Override
@@ -1082,6 +1087,10 @@ public class ExternalNavigationHandlerTest extends InstrumentationTestCase {
         }
 
         @Override
+        public void maybeSetAppHandlers(Intent intent, List<ResolveInfo> info) {
+        }
+
+        @Override
         public boolean isChromeAppInForeground() {
             return mIsChromeAppInForeground;
         }