Ignore kill termination status when shutting down a child process.

content/browser/browser_child_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.
 
 #include "content/browser/browser_child_process_host_impl.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/dump_without_crashing.h"
@@ skipping 377 matching lines @@
                                   PROCESS_TYPE_MAX);
         break;
       }
 #if defined(OS_ANDROID)
       case base::TERMINATION_STATUS_OOM_PROTECTED:
 #endif
 #if defined(OS_CHROMEOS)
       case base::TERMINATION_STATUS_PROCESS_WAS_KILLED_BY_OOM:
 #endif
       case base::TERMINATION_STATUS_PROCESS_WAS_KILLED: {
+        // If the IPC channel was disconnected after a shutdown request, we
+        // expect the process to be dead. However, if the IPC channel uses
+        // ChannelMojo, it is not true that the process is dead when the
+        // disconnection event comes in. This is because Mojo does an orderly
+        // shutdown in the child process and so the child may not be dead by the
+        // time we get here. If the child isn't dead, the call to
+        // GetTerminationStatus() above may cause the child to be killed because
+        // GetTerminationStatus(known_dead=true) SIGKILLs the process before
+        // waiting for it.
+        if (child_process_host_->IsShuttingDown())
+          break;
         delegate_->OnProcessCrashed(exit_code);
         BrowserThread::PostTask(
             BrowserThread::UI, FROM_HERE,
             base::Bind(&NotifyProcessKilled, data_, exit_code));
         // Report that this child process was killed.
         UMA_HISTOGRAM_ENUMERATION("ChildProcess.Killed2",
                                   data_.process_type,
                                   PROCESS_TYPE_MAX);
         break;
       }
       case base::TERMINATION_STATUS_STILL_RUNNING: {
         UMA_HISTOGRAM_ENUMERATION("ChildProcess.DisconnectedAlive2",
                                   data_.process_type,
                                   PROCESS_TYPE_MAX);
       }
       default:
         break;
     }
     UMA_HISTOGRAM_ENUMERATION("ChildProcess.Disconnected2",
                               data_.process_type,
                               PROCESS_TYPE_MAX);
 #if defined(OS_CHROMEOS)
-    if (status == base::TERMINATION_STATUS_PROCESS_WAS_KILLED_BY_OOM) {
+    if (status == base::TERMINATION_STATUS_PROCESS_WAS_KILLED_BY_OOM &&
+        !child_process_host_->IsShuttingDown()) {
       UMA_HISTOGRAM_ENUMERATION("ChildProcess.Killed2.OOM",
                                 data_.process_type,
                                 PROCESS_TYPE_MAX);
     }
 #endif
   }
   delete delegate_;  // Will delete us
 }
 
 bool BrowserChildProcessHostImpl::Send(IPC::Message* message) {
@@ skipping 40 matching lines @@
 
 #if defined(OS_WIN)
 
 void BrowserChildProcessHostImpl::OnObjectSignaled(HANDLE object) {
   OnChildDisconnected();
 }
 
 #endif
 
 }  // namespace content