Add a Cocoa version of the auto-dismissing dialog.

chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc

Index: chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
diff --git a/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc b/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
index 88ddb3606c54a3768827f2300345fcedd8613735..347ea52f9cda3d24357cea08de3201ff34fa70c2 100644
--- a/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
+++ b/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "base/feature_list.h"
 #include "base/metrics/histogram_macros.h"
+#include "build/build_config.h"
 #include "chrome/browser/engagement/site_engagement_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ -17,6 +18,11 @@
 #include "components/app_modal/javascript_dialog_manager.h"
 #include "content/public/browser/web_contents_delegate.h"
 
+#if defined(OS_MACOSX)
+#include "chrome/browser/ui/browser_dialogs.h"
+#include "chrome/browser/ui/javascript_dialogs/javascript_dialog_cocoa.h"
+#endif
+
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(JavaScriptDialogTabHelper);
 
 namespace {
@@ -99,10 +105,19 @@ void JavaScriptDialogTabHelper::RunJavaScriptDialog(
         AppModalDialogManager()->GetTitle(alerting_web_contents, origin_url);
     dialog_callback_ = callback;
     BrowserList::AddObserver(this);
-    // TODO(avi): abstract out so that we have a Mac version too...
-    dialog_ = JavaScriptDialogViews::Create(
-        parent_web_contents, alerting_web_contents, title, message_type,
-        message_text, default_prompt_text, callback);
+#if defined(OS_MACOSX)

[Robert Sesek, 2016/10/27 15:17:24]

Alternatively, this block could be in JavaScriptDialog::Create.

[Avi (use Gerrit), 2016/10/27 18:41:22]

Yes, that would be cleaner. Done.

+    if (!chrome::ToolkitViewsWebUIDialogsEnabled()) {
+      dialog_ = JavaScriptDialogCocoa::Create(
+          parent_web_contents, alerting_web_contents, title, message_type,
+          message_text, default_prompt_text, callback);
+    } else {
+#endif
+      dialog_ = JavaScriptDialogViews::Create(
+          parent_web_contents, alerting_web_contents, title, message_type,
+          message_text, default_prompt_text, callback);
+#if defined(OS_MACOSX)
+    }
+#endif
 
     // Message suppression is something that we don't give the user a checkbox
     // for any more. It was useful back in the day when dialogs were app-modal