Opening new "about:blank" tab if all tabs are closed in tab switcher mode.

chrome/android/shell/java/src/org/chromium/chrome/shell/TabManager.java

Index: chrome/android/shell/java/src/org/chromium/chrome/shell/TabManager.java
diff --git a/chrome/android/shell/java/src/org/chromium/chrome/shell/TabManager.java b/chrome/android/shell/java/src/org/chromium/chrome/shell/TabManager.java
index 36261cc03b48cde3361d813bbba1723c9ce3fe37..964304be00d3e93c77f0dcc68a77de4569304cc9 100644
--- a/chrome/android/shell/java/src/org/chromium/chrome/shell/TabManager.java
+++ b/chrome/android/shell/java/src/org/chromium/chrome/shell/TabManager.java
@@ -14,6 +14,7 @@ import android.view.inputmethod.InputMethodManager;
 import android.widget.FrameLayout;
 import android.widget.LinearLayout;
 
+import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.EmptyTabObserver;
 import org.chromium.chrome.browser.Tab;
 import org.chromium.chrome.browser.tabmodel.EmptyTabModelObserver;
@@ -57,6 +58,9 @@ public class TabManager extends LinearLayout {
         @Override
         public void willCloseTab(Tab tab, boolean animate) {
             if (tab == mCurrentTab) setCurrentTab(null);
+            if (mTabModelSelector.getCurrentModel().getCount() == 1) {
+                createNewTab();
+            }
         }
     };
 
@@ -144,6 +148,11 @@ public class TabManager extends LinearLayout {
         mTabModelSelector.getCurrentModel().closeAllTabs();
     }
 
+    @VisibleForTesting
+    public void closeTab() {
+        mTabModelSelector.getCurrentModel().closeTab(mCurrentTab);
+    }
+
     /**
      * Creates a {@link ChromeShellTab} with a URL specified by {@code url}.
      * @param url The URL the new {@link ChromeShellTab} should start with.