Use scoped_ptr for ShellWindowLinkDelegate to prevent memory leak.

chrome/browser/ui/apps/chrome_shell_window_delegate.cc

 // Copyright 2013 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/ui/apps/chrome_shell_window_delegate.h"
 
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
 #include "chrome/browser/file_select_helper.h"
 #include "chrome/browser/media/media_capture_devices_dispatcher.h"
@@ skipping 11 matching lines @@
 #if defined(USE_ASH)
 #include "ash/launcher/launcher_types.h"
 #endif
 
 namespace chrome {
 
 namespace {
 
 bool disable_external_open_for_testing_ = false;
 
-class ShellWindowLinkDelegate : public content::WebContentsDelegate {
- public:
-  ShellWindowLinkDelegate();
-
- private:
-  virtual content::WebContents* OpenURLFromTab(
-      content::WebContents* source,
-      const content::OpenURLParams& params) OVERRIDE;
-
-  DISALLOW_COPY_AND_ASSIGN(ShellWindowLinkDelegate);
-};
+}  // namespace
 
 ShellWindowLinkDelegate::ShellWindowLinkDelegate() {}
 
 // TODO(rockot): Add a test that exercises this code. See
 // http://crbug.com/254260.
 content::WebContents* ShellWindowLinkDelegate::OpenURLFromTab(
     content::WebContents* source,
     const content::OpenURLParams& params) {
   platform_util::OpenExternal(params.url);
   delete source;
   return NULL;
 }
 
-}  // namespace
-
 ChromeShellWindowDelegate::ChromeShellWindowDelegate() {}
 
 ChromeShellWindowDelegate::~ChromeShellWindowDelegate() {}
 
 void ChromeShellWindowDelegate::DisableExternalOpenForTesting() {
   disable_external_open_for_testing_ = true;
 }
 
 void ChromeShellWindowDelegate::InitWebContents(
     content::WebContents* web_contents) {
@@ skipping 17 matching lines @@
 }
 
 void ChromeShellWindowDelegate::AddNewContents(
     Profile* profile,
     content::WebContents* new_contents,
     WindowOpenDisposition disposition,
     const gfx::Rect& initial_pos,
     bool user_gesture,
     bool* was_blocked) {
   if (!disable_external_open_for_testing_) {
-    new_contents->SetDelegate(new ShellWindowLinkDelegate());
+    if (!shell_window_link_delegate_.get())
+      shell_window_link_delegate_.reset(new ShellWindowLinkDelegate());
+    new_contents->SetDelegate(shell_window_link_delegate_.get());

[sky, 2013/07/08 14:51:39]

What is the lifetime of new_contents?

[zhchbin, 2013/07/09 02:00:10]

It will be deleted when the ShellWindowLinkDelegate::OpenURLFromTab is called.

Line 42: delete source;

     return;
   }
   Browser* browser =
       chrome::FindOrCreateTabbedBrowser(profile, chrome::GetActiveDesktop());
   // Force all links to open in a new tab, even if they were trying to open a
   // new window.
   disposition =
       disposition == NEW_BACKGROUND_TAB ? disposition : NEW_FOREGROUND_TAB;
   chrome::AddWebContents(browser, NULL, new_contents, disposition, initial_pos,
                          user_gesture, was_blocked);
@@ skipping 38 matching lines @@
         host->GetRoutingID(), blocked));
   }
 }
 
 bool ChromeShellWindowDelegate::IsWebContentsVisible(
     content::WebContents* web_contents) {
   return platform_util::IsVisible(web_contents->GetView()->GetNativeView());
 }
 
 }  // namespace chrome