Avoid exiting the renderer process if it has a pending render view.

content/browser/renderer_host/render_process_host.h

 // Copyright (c) 2011 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 CONTENT_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_H_
 #pragma once
 
 #include <set>
 
@@ skipping 172 matching lines @@
 
   // Called when a received message cannot be decoded.
   virtual void ReceivedBadMessage() = 0;
 
   // Track the count of visible widgets. Called by listeners to register and
   // unregister visibility.
   virtual void WidgetRestored() = 0;
   virtual void WidgetHidden() = 0;
   virtual int VisibleWidgetCount() const = 0;
 
+  // Track the count of pending views that are being swapped back in.  Called
+  // by listeners to register and unregister pending views to prevent the
+  // process from exiting.
+  virtual void AddPendingView() = 0;

[Matt Perry, 2011/05/10 01:14:02]

since this is an interface on the class already, why not just make it
non-virtual and implement it here? The impl doesn't seem to do anything specific
to chrome.

[Charlie Reis, 2011/05/10 01:33:09]

Actually, I'm a little unclear on the difference between RenderProcessHost and
BrowserRenderProcessHost, since both are in content, not chrome.  Right now, the
test version in MockRPH doesn't care about this, so that's the difference
between the two.

John, if you agree that we should move the implementation here, I'm happy to do
that.

[jam, 2011/05/10 04:45:18]

RenderProcessHost was added so that we can have a mock object that implements
the bare interface and use it in tests instead of BrowserRenderProcessHost,
which actually launches processes etc.  I don't have strong opinions on where
the implementation goes.

[Charlie Reis, 2011/05/10 18:42:19]

Ok.  Since there's no harm in having these counters in the tests (and possibly
some value), I've moved the implementation to RenderProcessHost as Matt
suggests.

+  virtual void RemovePendingView() = 0;
+
   // Try to shutdown the associated renderer process as fast as possible.
   // If this renderer has any RenderViews with unload handlers, then this
   // function does nothing.  The current implementation uses TerminateProcess.
   // Returns True if it was able to do fast shutdown.
   virtual bool FastShutdownIfPossible() = 0;
 
   // Synchronously sends the message, waiting for the specified timeout. The
   // implementor takes ownership of the given Message regardless of whether or
   // not this method succeeds. Returns true on success.
   virtual bool SendWithTimeout(IPC::Message* msg, int timeout_ms) = 0;
@@ skipping 106 matching lines @@
 // Factory object for RenderProcessHosts. Using this factory allows tests to
 // swap out a different one to use a TestRenderProcessHost.
 class RenderProcessHostFactory {
  public:
   virtual ~RenderProcessHostFactory() {}
   virtual RenderProcessHost* CreateRenderProcessHost(
       Profile* profile) const = 0;
 };
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_H_