Fix: tabs slow to response to beforeunload are closed prematurely.

content/browser/web_contents/web_contents_impl.cc

 // Copyright (c) 2012 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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 4535 matching lines @@
 
   RenderFrameHostImpl* rfhi =
       static_cast<RenderFrameHostImpl*>(GetRenderViewHost()->GetMainFrame());
 
   // Ignore renderer unresponsive event if debugger is attached to the tab
   // since the event may be a result of the renderer sitting on a breakpoint.
   // See http://crbug.com/65458
   if (DevToolsAgentHost::IsDebuggerAttached(this))
     return;
 
-  if (rfhi->is_waiting_for_beforeunload_ack() ||
-      rfhi->IsWaitingForUnloadACK()) {
+  if (rfhi->is_waiting_for_beforeunload_ack()) {
+    // If the hang is in the beforeunload handler,

[Charlie Reis, 2016/05/19 22:11:56]

nit: Fix line wrap.

+    // pretend the beforeunload listeners have all fired and allow the delegate
+    // to continue closing; the user will not have the option of cancelling the
+    // close.
+    rfhi->ForceBeforeUnloadAck();
+    return;
+  }
+
+  if (rfhi->IsWaitingForUnloadACK()) {
     // Hang occurred while firing the beforeunload/unload handler.

[Charlie Reis, 2016/05/19 22:11:56]

nit: Drop "beforeunload/"

     // Pretend the handler fired so tab closing continues as if it had.
     GetRenderViewHost()->set_sudden_termination_allowed(true);
 
     if (!GetRenderManager()->ShouldCloseTabOnUnresponsiveRenderer())
       return;
 
-    // If the tab hangs in the beforeunload/unload handler there's really
-    // nothing we can do to recover. If the hang is in the beforeunload handler,
-    // pretend the beforeunload listeners have all fired and allow the delegate
-    // to continue closing; the user will not have the option of cancelling the
-    // close. Otherwise, pretend the unload listeners have all fired and close
+    // If the tab hangs in the unload handler there's really nothing we can do
+    // to recover. Pretend the unload listeners have all fired and close
     // the tab.
-    bool close = true;
-    if (rfhi->is_waiting_for_beforeunload_ack() && delegate_) {
-      delegate_->BeforeUnloadFired(this, true, &close);
-    }
-    if (close)
-      Close();
+    Close();
     return;
   }
 
   if (!GetRenderViewHost() || !GetRenderViewHost()->IsRenderViewLive())
     return;
 
   if (delegate_)
     delegate_->RendererUnresponsive(this);
 }
 
@@ skipping 446 matching lines @@
   for (RenderViewHost* render_view_host : render_view_host_set)
     render_view_host->OnWebkitPreferencesChanged();
 }
 
 void WebContentsImpl::SetJavaScriptDialogManagerForTesting(
     JavaScriptDialogManager* dialog_manager) {
   dialog_manager_ = dialog_manager;
 }
 
 }  // namespace content