Close web contents modal dialogs on content load start

components/web_modal/web_contents_modal_dialog_manager.h

Index: components/web_modal/web_contents_modal_dialog_manager.h
diff --git a/components/web_modal/web_contents_modal_dialog_manager.h b/components/web_modal/web_contents_modal_dialog_manager.h
index e2548c04e5cfc8b48bef516d9048aefea4f03052..00671b2db1a1956f10a686423a6626be45acf643 100644
--- a/components/web_modal/web_contents_modal_dialog_manager.h
+++ b/components/web_modal/web_contents_modal_dialog_manager.h
@@ -45,6 +45,11 @@ class WebContentsModalDialogManager
   // calling this function.
   void FocusTopmostDialog();
 
+  // Set to true to prevent closing the window when a page load starts on the
+  // WebContents.
+  void SetPreventCloseOnLoadStart(NativeWebContentsModalDialog dialog,
+                                  bool prevent);
+
   // Overriden from NativeWebContentsModalDialogManagerDelegate:
   virtual content::WebContents* GetWebContents() const OVERRIDE;
   // Called when a WebContentsModalDialogs we own is about to be closed.
@@ -76,7 +81,18 @@ class WebContentsModalDialogManager
   explicit WebContentsModalDialogManager(content::WebContents* web_contents);
   friend class content::WebContentsUserData<WebContentsModalDialogManager>;
 
-  typedef std::deque<NativeWebContentsModalDialog> WebContentsModalDialogList;
+  struct DialogState {
+    explicit DialogState(NativeWebContentsModalDialog dialog);
+
+    NativeWebContentsModalDialog dialog;
+    bool prevent_close_on_load_start;
+  };
+
+  typedef std::deque<DialogState> WebContentsModalDialogList;
+
+  // Utility function to get the dialog state for a dialog.
+  WebContentsModalDialogList::iterator FindDialogState(
+      NativeWebContentsModalDialog dialog);
 
   // Blocks/unblocks interaction with renderer process.
   void BlockWebContentsInteraction(bool blocked);
@@ -87,9 +103,6 @@ class WebContentsModalDialogManager
   void CloseAllDialogs();
 
   // Overridden from content::WebContentsObserver:
-  virtual void DidNavigateMainFrame(
-      const content::LoadCommittedDetails& details,
-      const content::FrameNavigateParams& params) OVERRIDE;
   virtual void DidGetIgnoredUIEvent() OVERRIDE;
   virtual void WebContentsDestroyed(content::WebContents* tab) OVERRIDE;