Add RecentTabsPageTest

chrome/android/java/src/org/chromium/chrome/browser/ntp/FakeRecentlyClosedTabManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/FakeRecentlyClosedTabManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/FakeRecentlyClosedTabManager.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/FakeRecentlyClosedTabManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..5b5d374dff3d995cc6934541c11a1e0bdfe52bbd
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/FakeRecentlyClosedTabManager.java
@@ -0,0 +1,58 @@
+// 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.ntp;
+
+import android.support.annotation.Nullable;
+
+import org.chromium.chrome.browser.tab.Tab;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A fake implementation of {@link RecentlyClosedTabManager} for testing purposes.
+ */
+public class FakeRecentlyClosedTabManager implements RecentlyClosedTabManager {
+    @Nullable
+    private Runnable mTabsUpdatedRunnable;
+    private List<RecentlyClosedTab> mTabs = new ArrayList<>();
+
+    @Override
+    public void setTabsUpdatedRunnable(@Nullable Runnable runnable) {
+        mTabsUpdatedRunnable = runnable;
+    }
+
+    @Override
+    public List<RecentlyClosedTab> getRecentlyClosedTabs(int maxTabCount) {
+        List<RecentlyClosedTab> tabs = new ArrayList<>();
+        for (int i = 0; i < maxTabCount && i < mTabs.size(); i++) {
+            tabs.add(mTabs.get(i));
+        }
+        return tabs;
+    }
+
+    @Override
+    public boolean openRecentlyClosedTab(
+            Tab tab, RecentlyClosedTab recentTab, int windowOpenDisposition) {
+        return false;
+    }
+
+    @Override
+    public void openRecentlyClosedTab() {}
+
+    @Override
+    public void clearRecentlyClosedTabs() {
+        mTabs.clear();
+        if (mTabsUpdatedRunnable != null) mTabsUpdatedRunnable.run();
+    }
+
+    @Override
+    public void destroy() {}
+
+    public void setRecentlyClosedTabs(List<RecentlyClosedTab> tabs) {
+        mTabs = new ArrayList<>(tabs);
+        if (mTabsUpdatedRunnable != null) mTabsUpdatedRunnable.run();
+    }
+}