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

chrome/browser/chromeos/attestation/platform_verification_dialog.h

Index: chrome/browser/chromeos/attestation/platform_verification_dialog.h
diff --git a/chrome/browser/chromeos/attestation/platform_verification_dialog.h b/chrome/browser/chromeos/attestation/platform_verification_dialog.h
index d283c73427d82f2a3230db6670dbc6163e89b9e9..856878445e7e99b6d34ceb40e53c24293f5e3630 100644
--- a/chrome/browser/chromeos/attestation/platform_verification_dialog.h
+++ b/chrome/browser/chromeos/attestation/platform_verification_dialog.h
@@ -12,8 +12,6 @@
 #include "ui/views/controls/styled_label_listener.h"
 #include "ui/views/window/dialog_delegate.h"
 
-class Browser;
-
 namespace content {
 class WebContents;
 }
@@ -35,7 +33,7 @@ class PlatformVerificationDialog : public views::DialogDelegateView,
 
  private:
   PlatformVerificationDialog(
-      Browser* browser,
+      content::WebContents* web_contents,
       const base::string16& domain,
       const PlatformVerificationFlow::Delegate::ConsentCallback& callback);
 
@@ -56,7 +54,7 @@ class PlatformVerificationDialog : public views::DialogDelegateView,
   virtual void StyledLabelLinkClicked(const gfx::Range& range,
                                       int event_flags) OVERRIDE;
 
-  Browser* browser_;
+  content::WebContents* web_contents_;
   base::string16 domain_;
   PlatformVerificationFlow::Delegate::ConsentCallback callback_;