Reuse existing NTP if one exists

chrome/browser/browser.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/browser/browser.h"
 
 #if defined(OS_WIN)
 #include <shellapi.h>
 #include <windows.h>
 #endif  // OS_WIN
@@ skipping 2074 matching lines @@
 // Browser, CommandUpdater::CommandUpdaterDelegate implementation:
 
 void Browser::ExecuteCommand(int id) {
   ExecuteCommandWithDisposition(id, CURRENT_TAB);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // Browser, TabStripModelDelegate implementation:
 
 TabContents* Browser::AddBlankTab(bool foreground) {
+  // To make a more "launchy" experience, try to reuse an existing NTP if there
+  // is one.
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableExtensionApps)) {
+    for (int i = tabstrip_model_.count() - 1; i >= 0; --i) {
+      TabContents* contents = tabstrip_model_.GetTabContentsAt(i);
+      if (StartsWithASCII(contents->GetURL().spec(),
+                          chrome::kChromeUINewTabURL, true)) {
+        if (foreground)
+          SelectTabContentsAt(i, true);
+
+        return contents;
+      }
+    }
+  }
+
   return AddBlankTabAt(-1, foreground);
 }
 
 TabContents* Browser::AddBlankTabAt(int index, bool foreground) {
   // Time new tab page creation time.  We keep track of the timing data in
   // TabContents, but we want to include the time it takes to create the
   // TabContents object too.
   base::TimeTicks new_tab_start_time = base::TimeTicks::Now();
   TabContents* tab_contents = AddTabWithURL(
       GURL(chrome::kChromeUINewTabURL), GURL(), PageTransition::TYPED, index,
@@ skipping 1747 matching lines @@
   if (TabHasUnloadListener(contents)) {
     // If the page has unload listeners, then we tell the renderer to fire
     // them. Once they have fired, we'll get a message back saying whether
     // to proceed closing the page or not, which sends us back to this method
     // with the HasUnloadListener bit cleared.
     contents->render_view_host()->FirePageBeforeUnload(false);
     return true;
   }
   return false;
 }