Clear the pending_and_current_web_ui_ if we reuse it.

content/browser/frame_host/render_frame_host_manager.cc

 // Copyright 2013 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/frame_host/render_frame_host_manager.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 995 matching lines @@
   // renderer to suppress any further dialogs until it is swapped out.  However,
   // crash reports indicate that it's still possible for modal dialogs to exist
   // at this point, which poses a risk if we delete their RenderViewHost below.
   // Cancel them again to be safe.  http://crbug.com/324320.
   delegate_->CancelModalDialogsForRenderManager();
 
   // Next commit the Web UI, if any. Either replace |web_ui_| with
   // |pending_web_ui_|, or clear |web_ui_| if there is no pending WebUI, or
   // leave |web_ui_| as is if reusing it.
   DCHECK(!(pending_web_ui_.get() && pending_and_current_web_ui_.get()));
-  if (pending_web_ui_)
+  if (pending_web_ui_) {
     web_ui_.reset(pending_web_ui_.release());
-  else if (!pending_and_current_web_ui_.get())
+  } else if (!pending_and_current_web_ui_.get()) {
     web_ui_.reset();
+  } else {
+    DCHECK_EQ(pending_and_current_web_ui_.get(), web_ui_.get());
+    pending_and_current_web_ui_.reset();
+  }
 
   // It's possible for the pending_render_frame_host_ to be NULL when we aren't
   // crossing process boundaries. If so, we just needed to handle the Web UI
   // committing above and we're done.
   if (!pending_render_frame_host_) {
     if (will_focus_location_bar)
       delegate_->SetFocusToLocationBar(false);
     return;
   }
 
@@ skipping 411 matching lines @@
     SiteInstance* instance) const {
   RenderFrameHostMap::const_iterator iter =
       swapped_out_hosts_.find(instance->GetId());
   if (iter != swapped_out_hosts_.end())
     return iter->second;
 
   return NULL;
 }
 
 }  // namespace content