Fixes the crash for "learn more" link of the dialog for v2 apps.

chrome/browser/chromeos/attestation/platform_verification_dialog.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_ATTESTATION_PLATFORM_VERIFICATION_DIALOG_H_
 #define CHROME_BROWSER_CHROMEOS_ATTESTATION_PLATFORM_VERIFICATION_DIALOG_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/chromeos/attestation/platform_verification_flow.h"
 #include "ui/views/controls/styled_label_listener.h"
 #include "ui/views/window/dialog_delegate.h"
 
-class Browser;
-
 namespace content {
 class WebContents;
 }
 
 namespace chromeos {
 namespace attestation {
 
 // A tab-modal dialog UI to ask the user for PlatformVerificationFlow.
 class PlatformVerificationDialog : public views::DialogDelegateView,
                                    public views::StyledLabelListener {
  public:
   // Initializes a tab-modal dialog for |web_contents| and shows it.
   static void ShowDialog(
       content::WebContents* web_contents,
       const PlatformVerificationFlow::Delegate::ConsentCallback& callback);
 
  protected:
   virtual ~PlatformVerificationDialog();
 
  private:
   PlatformVerificationDialog(
-      Browser* browser,
+      content::WebContents* web_contents,
       const base::string16& domain,
       const PlatformVerificationFlow::Delegate::ConsentCallback& callback);
 
   // Overridden from views::DialogDelegate:
   virtual bool Cancel() OVERRIDE;
   virtual bool Accept() OVERRIDE;
   virtual bool Close() OVERRIDE;
   virtual base::string16 GetDialogButtonLabel(
       ui::DialogButton button) const OVERRIDE;
 
   // Overridden from views::WidgetDelegate:
   virtual ui::ModalType GetModalType() const OVERRIDE;
 
   // Overridden from views::View:
   virtual gfx::Size GetPreferredSize() OVERRIDE;
 
   // Overridden from views::StyledLabelListener:
   virtual void StyledLabelLinkClicked(const gfx::Range& range,
                                       int event_flags) OVERRIDE;
 
-  Browser* browser_;
+  content::WebContents* web_contents_;
   base::string16 domain_;
   PlatformVerificationFlow::Delegate::ConsentCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformVerificationDialog);
 };
 
 }  // namespace attestation
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_ATTESTATION_PLATFORM_VERIFICATION_DIALOG_H_