Add histogram for how tab closing time. Did some cleanup along the way.

chrome/browser/renderer_host/render_view_host.h

 // Copyright (c) 2009 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.
 
 #ifndef CHROME_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_H_
 #define CHROME_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 621 matching lines @@
   // We only buffer a suspended navigation message while we a pending RVH for a
   // TabContents.  There will only ever be one suspended navigation, because
   // TabContents will destroy the pending RVH and create a new one if a second
   // navigation occurs.
   scoped_ptr<ViewMsg_Navigate> suspended_nav_message_;
 
   // If we were asked to RunModal, then this will hold the reply_msg that we
   // must return to the renderer to unblock it.
   IPC::Message* run_modal_reply_msg_;
 
-  // Set to true when there is an active "before unload" dialog.  When true,
-  // we've forced the throbber to start in Navigate, and we need to remember to
-  // turn it off in JavaScriptMessageBoxClosed if the navigation is canceled.
-  bool is_showing_before_unload_dialog_;

[tony, 2009/10/14 23:20:06]

Nit: Can you explain why this moved in the change description?

[jam, 2009/10/14 23:31:11]

Oh, that doesn't fix any bug.  It's just convenient so that the flag is in
tab_contents, which is where I want to do the time related code.  I needed a
flag there to know when a before unload dialog closes, to reset the time.  Added
a comment to the description.

-
   // Set to true when there is a pending ViewMsg_ShouldClose message pending.
   // This ensures we don't spam the renderer many times to close. When true,
   // the value of unload_ack_is_for_cross_site_transition_ indicates which type
   // of unload this is for.
   bool is_waiting_for_unload_ack_;
 
   // Valid only when is_waiting_for_unload_ack_ is true, this tells us if the
   // unload request is for closing the entire tab ( = false), or only this
   // RenderViewHost in the case of a cross-site transition ( = true).
   bool unload_ack_is_for_cross_site_transition_;
 
   bool are_javascript_messages_suppressed_;
 
   // True if the render view can be shut down suddenly.
   bool sudden_termination_allowed_;
 
   // DevTools triggers this mode when user chooses inspect lens tool.
   // While in this mode, mouse click is converted into InspectElement
   // command.
   bool in_inspect_element_mode_;
 
   NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHost);
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_H_