Don't make classes derive from ChildProcessHost, and instead have them use it through composition...

chrome/browser/nacl_host/nacl_process_host.cc

 // 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.
 
 #include "build/build_config.h"
 
 #include "chrome/browser/nacl_host/nacl_process_host.h"
 
 #if defined(OS_POSIX)
 #include <fcntl.h>
 #endif
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "base/win/windows_version.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/nacl_cmd_line.h"
 #include "chrome/common/nacl_messages.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/browser/renderer_host/chrome_render_message_filter.h"
+#include "content/common/child_process_host.h"
 #include "ipc/ipc_switches.h"
 #include "native_client/src/shared/imc/nacl_imc.h"
 
 #if defined(OS_POSIX)
 #include "ipc/ipc_channel_posix.h"
 #elif defined(OS_WIN)
 #include "chrome/browser/nacl_host/nacl_broker_service_win.h"
 #endif
 
 using content::BrowserThread;
@@ skipping 73 matching lines @@
 
 NaClProcessHost::NaClProcessHost(const std::wstring& url)
     : BrowserChildProcessHost(content::PROCESS_TYPE_NACL_LOADER),
       reply_msg_(NULL),
       internal_(new NaClInternal()),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
   set_name(WideToUTF16Hack(url));
 }
 
 NaClProcessHost::~NaClProcessHost() {
+  int exit_code;
+  GetChildTerminationStatus(&exit_code);
+  std::string message =
+      base::StringPrintf("NaCl process exited with status %i (0x%x)",
+                         exit_code, exit_code);
+  if (exit_code == 0) {
+    LOG(INFO) << message;
+  } else {
+    LOG(ERROR) << message;
+  }
+
+#if defined(OS_WIN)
+  NaClBrokerService::GetInstance()->OnLoaderDied();
+#endif
+
   for (size_t i = 0; i < internal_->sockets_for_renderer.size(); i++) {
     if (nacl::Close(internal_->sockets_for_renderer[i]) != 0) {
       LOG(ERROR) << "nacl::Close() failed";
     }
   }
   for (size_t i = 0; i < internal_->sockets_for_sel_ldr.size(); i++) {
     if (nacl::Close(internal_->sockets_for_sel_ldr[i]) != 0) {
       LOG(ERROR) << "nacl::Close() failed";
     }
   }
@@ skipping 76 matching lines @@
   if (!LaunchSelLdr()) {
     return false;
   }
   chrome_render_message_filter_ = chrome_render_message_filter;
   reply_msg_ = reply_msg;
 
   return true;
 }
 
 bool NaClProcessHost::LaunchSelLdr() {
-  if (!CreateChannel())
+  if (!child_process_host()->CreateChannel())
     return false;
 
   CommandLine::StringType nacl_loader_prefix;
 #if defined(OS_POSIX)
   nacl_loader_prefix = CommandLine::ForCurrentProcess()->GetSwitchValueNative(
       switches::kNaClLoaderCmdPrefix);
 #endif  // defined(OS_POSIX)
 
   // Build command line for nacl.
 
 #if defined(OS_MACOSX)
   // The Native Client process needs to be able to allocate a 1GB contiguous
   // region to use as the client environment's virtual address space. ASLR
   // (PIE) interferes with this by making it possible that no gap large enough
   // to accomodate this request will exist in the child process' address
   // space. Disable PIE for NaCl processes. See http://crbug.com/90221 and
   // http://code.google.com/p/nativeclient/issues/detail?id=2043.
   int flags = CHILD_NO_PIE;
 #elif defined(OS_LINUX)
-  int flags = nacl_loader_prefix.empty() ? CHILD_ALLOW_SELF : CHILD_NORMAL;
+  int flags = nacl_loader_prefix.empty() ? ChildProcessHost::CHILD_ALLOW_SELF :
+                                           ChildProcessHost::CHILD_NORMAL;
 #else
-  int flags = CHILD_NORMAL;
+  int flags = ChildProcessHost::CHILD_NORMAL;
 #endif
 
-  FilePath exe_path = GetChildPath(flags);
+  FilePath exe_path = ChildProcessHost::GetChildPath(flags);
   if (exe_path.empty())
     return false;
 
   CommandLine* cmd_line = new CommandLine(exe_path);
   nacl::CopyNaClCommandLineArguments(cmd_line);
 
   cmd_line->AppendSwitchASCII(switches::kProcessType,
                               switches::kNaClLoaderProcess);
-  cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id());
+  cmd_line->AppendSwitchASCII(switches::kProcessChannelID,
+                              child_process_host()->channel_id());
   if (logging::DialogsAreSuppressed())
     cmd_line->AppendSwitch(switches::kNoErrorDialogs);
 
   if (!nacl_loader_prefix.empty())
     cmd_line->PrependWrapper(nacl_loader_prefix);
 
   // On Windows we might need to start the broker process to launch a new loader
 #if defined(OS_WIN)
   if (RunningOnWOW64()) {
     return NaClBrokerService::GetInstance()->LaunchLoader(
-        this, ASCIIToWide(channel_id()));
+        this, ASCIIToWide(child_process_host()->channel_id()));
   } else {
     BrowserChildProcessHost::Launch(FilePath(), cmd_line);
   }
 #elif defined(OS_POSIX)
   BrowserChildProcessHost::Launch(nacl_loader_prefix.empty(),  // use_zygote
                                   base::environment_vector(),
                                   cmd_line);
 #endif
 
   return true;
 }
 
 void NaClProcessHost::OnProcessLaunchedByBroker(base::ProcessHandle handle) {
   set_handle(handle);
   OnProcessLaunched();
 }
 
 base::TerminationStatus NaClProcessHost::GetChildTerminationStatus(
     int* exit_code) {
   if (RunningOnWOW64())
     return base::GetTerminationStatus(handle(), exit_code);
   return BrowserChildProcessHost::GetChildTerminationStatus(exit_code);
 }
 
-void NaClProcessHost::OnChildDied() {
-  int exit_code;
-  GetChildTerminationStatus(&exit_code);
-  std::string message =
-    base::StringPrintf("NaCl process exited with status %i (0x%x)",
-                       exit_code, exit_code);
-  if (exit_code == 0) {
-    LOG(INFO) << message;
-  } else {
-    LOG(ERROR) << message;
-  }
-
-#if defined(OS_WIN)
-  NaClBrokerService::GetInstance()->OnLoaderDied();
-#endif
-  BrowserChildProcessHost::OnChildDied();
-}
-
 // This only ever runs on the BrowserThread::FILE thread.
 // If multiple tasks are posted, the later ones are no-ops.
 void NaClBrowser::OpenIrtLibraryFile() {
   if (irt_platform_file_ != base::kInvalidPlatformFileValue)
     // We've already run.
     return;
 
   FilePath irt_filepath;
 
   // Allow the IRT library to be overridden via an environment
@@ skipping 199 matching lines @@
 #endif
 
   Send(new NaClProcessMsg_Start(handles_for_sel_ldr));
   internal_->sockets_for_sel_ldr.clear();
 }
 
 bool NaClProcessHost::OnMessageReceived(const IPC::Message& msg) {
   NOTREACHED() << "Invalid message with type = " << msg.type();
   return false;
 }
-
-bool NaClProcessHost::CanShutdown() {
-  return true;
-}