Makes instant run before unload listeners.

chrome/browser/tab_contents/tab_contents.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/tab_contents/tab_contents.h"
 
 #include <cmath>
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
@@ skipping 822 matching lines @@
 void TabContents::HideContents() {
   // TODO(pkasting): http://b/1239839  Right now we purposefully don't call
   // our superclass HideContents(), because some callers want to be very picky
   // about the order in which these get called.  In addition to making the code
   // here practically impossible to understand, this also means we end up
   // calling TabContents::WasHidden() twice if callers call both versions of
   // HideContents() on a TabContents.
   WasHidden();
 }
 
+bool TabContents::NeedToFireBeforeUnload() {
+  return notify_disconnection() &&
+      !showing_interstitial_page() &&

[Charlie Reis, 2010/12/08 01:26:12]

Why is this line necessary?  I think we run unload handlers after the user
decides to proceed on an interstitial page.

[sky, 2010/12/08 03:04:22]

No idea there. This code comes directly from Browser. I'm assuming whoever wrote
it knew what they were doing.

[Charlie Reis, 2010/12/08 05:50:11]

Oh!  Well, it doesn't sound right to me, since the unload handler of the page
before the interstitial will never run because of this.  I'd suggest either
fixing it now (and manually checking that it's an improvement), or putting a
"TODO(creis): Should we fire even for interstitial pages?"

+      !render_view_host()->SuddenTerminationAllowed();

[Charlie Reis, 2010/12/08 01:26:12]

Doesn't this catch both the beforeunload and unload case?  In that case, perhaps
this should be called something like NeedToFireUnloadHandlers()?

[sky, 2010/12/08 03:04:22]

Yes.
I considered that, but then it doesn't really imply before unload listener
either. I went with updating the comment. Are you ok with that?

[Charlie Reis, 2010/12/08 05:50:11]

Yep, the improved comment is enough-- thanks.

+}
+
 void TabContents::OpenURL(const GURL& url, const GURL& referrer,
                           WindowOpenDisposition disposition,
                           PageTransition::Type transition) {
   if (delegate_)
     delegate_->OpenURLFromTab(this, url, referrer, disposition, transition);
 }
 
 bool TabContents::NavigateToPendingEntry(
     NavigationController::ReloadType reload_type) {
   return NavigateToEntry(*controller_.pending_entry(), reload_type);
@@ skipping 1925 matching lines @@
                             default_prompt, show_suppress_checkbox, reply_msg);
   } else {
     // If we are suppressing messages, just reply as is if the user immediately
     // pressed "Cancel".
     OnMessageBoxClosed(reply_msg, false, std::wstring());
   }
 }
 
 void TabContents::RunBeforeUnloadConfirm(const std::wstring& message,
                                          IPC::Message* reply_msg) {
+  if (delegate())
+    delegate()->WillRunBeforeUnloadConfirm();
   if (delegate() && delegate()->ShouldSuppressDialogs()) {
     render_view_host()->JavaScriptMessageBoxClosed(reply_msg, true,
                                                    std::wstring());
     return;
   }
   is_showing_before_unload_dialog_ = true;
   RunBeforeUnloadDialog(this, message, reply_msg);
 }
 
 void TabContents::ShowModalHTMLDialog(const GURL& url, int width, int height,
@@ skipping 445 matching lines @@
 }
 
 void TabContents::set_encoding(const std::string& encoding) {
   encoding_ = CharacterEncoding::GetCanonicalEncodingNameByAliasName(encoding);
 }
 
 void TabContents::SetAppIcon(const SkBitmap& app_icon) {
   app_icon_ = app_icon;
   NotifyNavigationStateChanged(INVALIDATE_TITLE);
 }