Dying RenderProcessHostImpls should not send observer notifications.

content/browser/renderer_host/render_process_host_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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 2302 matching lines @@
   // is fixed.
   tracked_objects::ScopedTracker tracking_profile7(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "465841 RenderProcessHostImpl::OnProcessLaunched::EnableAec"));
   if (WebRTCInternals::GetInstance()->aec_dump_enabled())
     EnableAecDump(WebRTCInternals::GetInstance()->aec_dump_file_path());
 #endif
 }
 
 void RenderProcessHostImpl::OnProcessLaunchFailed() {
+  // If this object will be destructed soon, then observers have already been
+  // sent a RenderProcessHostDestroyed notification, and we must observe our
+  // contract that says that will be the last call.
+  if (deleting_soon_)
+    return;
+
   RendererClosedDetails details { base::TERMINATION_STATUS_PROCESS_WAS_KILLED,
                                   -1 };
   ProcessDied(true, &details);
 }
 
 scoped_refptr<AudioRendererHost>
 RenderProcessHostImpl::audio_renderer_host() const {
   return audio_renderer_host_;
 }
 
@@ skipping 121 matching lines @@
   if (worker_ref_count_ == 0)
     Cleanup();
 }
 
 void RenderProcessHostImpl::GetAudioOutputControllers(
     const GetAudioOutputControllersCallback& callback) const {
   audio_renderer_host()->GetOutputControllers(callback);
 }
 
 }  // namespace content