Factor out uses of the WebContentsModalDialog interface from platform-independent code

chrome/browser/ui/views/login_prompt_views.cc

Index: chrome/browser/ui/views/login_prompt_views.cc
diff --git a/chrome/browser/ui/views/login_prompt_views.cc b/chrome/browser/ui/views/login_prompt_views.cc
index aa026ee1647a07a5edfb0c0a05c3c4a206261e0b..8ae11a8d998c93012b0576be1882d9abe485040d 100644
--- a/chrome/browser/ui/views/login_prompt_views.cc
+++ b/chrome/browser/ui/views/login_prompt_views.cc
@@ -35,7 +35,8 @@ class LoginHandlerViews : public LoginHandler,
  public:
   LoginHandlerViews(net::AuthChallengeInfo* auth_info, net::URLRequest* request)
       : LoginHandler(auth_info, request),
-        login_view_(NULL) {
+        login_view_(NULL),
+        dialog_(NULL) {
   }
 
   // LoginModelObserver implementation.
@@ -64,7 +65,7 @@ class LoginHandlerViews : public LoginHandler,
       tab->GetRenderViewHost()->SetIgnoreInputEvents(false);
 
     // Reference is no longer valid.
-    SetDialog(NULL);
+    dialog_ = NULL;
 
     CancelAuth();
   }
@@ -73,7 +74,7 @@ class LoginHandlerViews : public LoginHandler,
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
     // The constrained window is going to delete itself; clear our pointer.
-    SetDialog(NULL);
+    dialog_ = NULL;
     SetModel(NULL);
 
     ReleaseSoon();
@@ -135,10 +136,16 @@ class LoginHandlerViews : public LoginHandler,
     // will occur via an InvokeLater on the UI thread, which is guaranteed
     // to happen after this is called (since this was InvokeLater'd first).
     WebContents* requesting_contents = GetWebContentsForLogin();
-    SetDialog(ConstrainedWindowViews::Create(requesting_contents, this));
+    dialog_ = ConstrainedWindowViews::Create(requesting_contents, this);
     NotifyAuthNeeded();
   }
 
+  virtual void CloseDialog() OVERRIDE {
+    // The hosting WebContentsModalDialog may have been freed.
+    if (dialog_)
+      dialog_->CloseWebContentsModalDialog();
+  }
+
  private:
   friend class base::RefCountedThreadSafe<LoginHandlerViews>;
   friend class LoginPrompt;
@@ -148,6 +155,8 @@ class LoginHandlerViews : public LoginHandler,
   // The LoginView that contains the user's login information
   LoginView* login_view_;
 
+  ConstrainedWindowViews* dialog_;
+
   DISALLOW_COPY_AND_ASSIGN(LoginHandlerViews);
 };