Make JavaScript dialogs auto-dismiss on tab switch.

chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.h

Index: chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.h
diff --git a/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.h b/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.h
index 4a75f5bf94b4255cfe471d4263f7c1ec2d95d3ba..5a00f203c983ecc50ebe5fd9c266bbce20f3a0ae 100644
--- a/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.h
+++ b/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.h
@@ -5,13 +5,20 @@
 #ifndef CHROME_BROWSER_UI_JAVASCRIPT_DIALOGS_JAVASCRIPT_DIALOG_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_JAVASCRIPT_DIALOGS_JAVASCRIPT_DIALOG_TAB_HELPER_H_
 
+#include <memory>
+
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/ui/browser_list_observer.h"
 #include "content/public/browser/javascript_dialog_manager.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
+class JavaScriptDialogViews;
+
 class JavaScriptDialogTabHelper

[Peter Kasting, 2016/10/17 20:16:05]

Nit: While here: Would be nice to have an overview comment about the purpose of
this class.

[Avi (use Gerrit), 2016/10/18 02:46:41]

Done.

     : public content::WebContentsObserver,
+      public chrome::BrowserListObserver,
       public content::JavaScriptDialogManager,
       public content::WebContentsUserData<JavaScriptDialogTabHelper> {
  public:
@@ -35,11 +42,27 @@ class JavaScriptDialogTabHelper
   void CancelDialogs(content::WebContents* web_contents,
                      bool suppress_callbacks,
                      bool reset_state) override;
-  void WebContentsDestroyed() override;
+
+  // WebContentsObserver:

[Peter Kasting, 2016/10/17 20:16:04]

Nit: Keep blocks of overrides and superclass list in same order

[Avi (use Gerrit), 2016/10/18 02:46:41]

Done.

+  void WasHidden() override;
+
+  // BrowserListObserver:
+  void OnBrowserSetLastActive(Browser* browser) override;
 
  private:
   friend class content::WebContentsUserData<JavaScriptDialogTabHelper>;
 
+  void CloseDialog(bool suppress_callback,
+                   bool success,
+                   const base::string16& user_input);
+
+  // The dialog being displayed on the observed WebContents.
+  base::WeakPtr<JavaScriptDialogViews> dialog_;
+
+  // The callback provided for when the dialog is closed. Usually the dialog
+  // itself calls it, but this class will do in some cases.

[Peter Kasting, 2016/10/17 20:16:05]

Nit: "will do it" or "will do so".  Would be nice to refer to some comment
elsewhere that would make it clear what these kinds of cases might be (e.g. the
class overview comment mentioned above?).

[Avi (use Gerrit), 2016/10/18 02:46:41]

Done.

+  content::JavaScriptDialogManager::DialogClosedCallback dialog_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(JavaScriptDialogTabHelper);
 };