Links in platform apps should open in the system default browser.

chrome/browser/extensions/platform_app_browsertest_util.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_PLATFORM_APP_BROWSERTEST_UTIL_H_
 #define CHROME_BROWSER_EXTENSIONS_PLATFORM_APP_BROWSERTEST_UTIL_H_
 
 
 #include "chrome/browser/extensions/extension_apitest.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_window.h"
 
 
 namespace content {
 class WebContents;
 }
 
 class CommandLine;
 class ShellWindow;
 
 namespace extensions {
 class Extension;
 
+class MockExternalUrlController : public content::WebContentsDelegate {

[Mihai Parparita -not on Chrome, 2012/10/12 23:00:17]

This doesn't need to be defined in the header, it can just be in the .cc file
(you can just have a forward declaration here).

+ public:
+   MockExternalUrlController() {}
+
+ private:
+  // content::WebContentsDelegate implementation.
+  virtual content::WebContents* OpenURLFromTab(
+      content::WebContents* source,
+      const content::OpenURLParams& params) OVERRIDE {
+    // Delete useless web content first to
+    // avoid a potential leak in a render process host.
+    delete source;
+
+    // Force to open in a new tab.
+    WindowOpenDisposition disposition = params.disposition;
+    content::OpenURLParams new_tab_params = params;
+    new_tab_params.disposition =
+        disposition == NEW_BACKGROUND_TAB ? disposition : NEW_FOREGROUND_TAB;
+    for (BrowserList::const_iterator i = BrowserList::begin();
+        i != BrowserList::end(); ++i) {
+      if ((*i)->is_type_tabbed()) {
+        Browser* browser = *i;
+        content::WebContents* new_tab = browser->OpenURL(new_tab_params);
+        browser->window()->Show();
+        return new_tab;
+      }
+    }
+    return NULL;
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(MockExternalUrlController);
+};
+
 class PlatformAppBrowserTest : public ExtensionApiTest {
  public:
   virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE;
+  virtual void SetUpOnMainThread() OVERRIDE;
 
  protected:
   // Runs the app named |name| out of the platform_apps subdirectory. Waits
   // until it is launched.
   const Extension* LoadAndLaunchPlatformApp(const char* name);
 
   // Installs and runs the app named |name| out of the platform_apps
   // subdirectory. Waits until it is launched.
   const Extension* InstallAndLaunchPlatformApp(const char* name);
 
@@ skipping 24 matching lines @@
   void ClearCommandLineArgs();
 
   // Sets up the command line for running platform apps.
   void SetCommandLineArg(const std::string& test_file);
 
   // Creates an empty shell window for |extension|.
   ShellWindow* CreateShellWindow(const Extension* extension);
 
   // Closes |window| and waits until it's gone.
   void CloseShellWindow(ShellWindow* window);
+
+  scoped_ptr<MockExternalUrlController> mock_external_url_controller_;
 };
 
 }
 
 #endif  // CHROME_BROWSER_EXTENSIONS_PLATFORM_APP_BROWSERTEST_UTIL_H_