Revert of Fixes redirects to external apps when navigating from PWA.

chrome/android/javatests/src/org/chromium/chrome/browser/webapps/TopActivityListener.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/webapps/TopActivityListener.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/webapps/TopActivityListener.java b/chrome/android/javatests/src/org/chromium/chrome/browser/webapps/TopActivityListener.java
new file mode 100644
index 0000000000000000000000000000000000000000..e746f7ef9e885cf561e4b790229c33aee216002c
--- /dev/null
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/webapps/TopActivityListener.java
@@ -0,0 +1,64 @@
+// Copyright 2017 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.webapps;
+
+import android.app.Activity;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+import org.chromium.base.ActivityState;
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ApplicationStatus.ActivityStateListener;
+import org.chromium.content.browser.test.util.Criteria;
+import org.chromium.content.browser.test.util.CriteriaHelper;
+
+import javax.annotation.Nullable;
+
+/**
+ * Test rule tracking which Chrome activity is currently at the top of the task.
+ */
+public class TopActivityListener implements TestRule {
+    private final ActivityStateListener mListener = new ActivityStateListener() {
+        @Override
+        public void onActivityStateChange(Activity activity, int newState) {
+            if (newState == ActivityState.RESUMED) {
+                mMostRecentActivity = activity;
+            }
+        }
+    };
+
+    private Activity mMostRecentActivity;
+
+    @Override
+    public Statement apply(final Statement base, Description description) {
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                ApplicationStatus.registerStateListenerForAllActivities(mListener);
+                base.evaluate();
+                ApplicationStatus.unregisterActivityStateListener(mListener);
+            }
+        };
+    }
+
+    @Nullable
+    public Activity getMostRecentActivity() {
+        return mMostRecentActivity;
+    }
+
+    @SuppressWarnings("unchecked")
+    public <T extends Activity> T waitFor(final Class<T> expectedActivityClass) {
+        CriteriaHelper.pollUiThread(new Criteria() {
+            @Override
+            public boolean isSatisfied() {
+                return mMostRecentActivity != null
+                        && expectedActivityClass.isAssignableFrom(mMostRecentActivity.getClass());
+            }
+        });
+        return (T) mMostRecentActivity;
+    }
+}