Make utility process run in-process when running in single-process mode.

content/utility/utility_thread_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/utility/utility_thread_impl.h"
 
 #include <stddef.h>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_vector.h"
 #include "content/child/child_process.h"
 #include "content/child/webkitplatformsupport_impl.h"
 #include "content/common/child_process_messages.h"
 #include "content/common/utility_messages.h"
+#include "content/public/common/content_switches.h"
 #include "content/public/utility/content_utility_client.h"
 #include "third_party/WebKit/public/web/WebKit.h"
 #include "webkit/plugins/npapi/plugin_list.h"
 
 #if defined(TOOLKIT_GTK)
 #include <gtk/gtk.h>
 
 #include "ui/gfx/gtk_util.h"
 #endif
 
 namespace content {
 
 namespace {
 
 template<typename SRC, typename DEST>
 void ConvertVector(const SRC& src, DEST* dest) {
   dest->reserve(src.size());
   for (typename SRC::const_iterator i = src.begin(); i != src.end(); ++i)
     dest->push_back(typename DEST::value_type(*i));
 }
 
 }  // namespace
 
-UtilityThreadImpl::UtilityThreadImpl()
-    : batch_mode_(false) {
-  ChildProcess::current()->AddRefProcess();
-  webkit_platform_support_.reset(new WebKitPlatformSupportImpl);
-  WebKit::initialize(webkit_platform_support_.get());
-  GetContentClient()->utility()->UtilityThreadStarted();
+UtilityThreadImpl::UtilityThreadImpl() : initialize_webkit_(true) {
+  Init();
+}
+
+UtilityThreadImpl::UtilityThreadImpl(const std::string& channel_name)
+    : ChildThread(channel_name),
+      initialize_webkit_(false) {
+  Init();
 }
 
 UtilityThreadImpl::~UtilityThreadImpl() {
 }
 
 void UtilityThreadImpl::Shutdown() {
-  WebKit::shutdown();
+  if (initialize_webkit_)
+    WebKit::shutdown();
 }
 
 bool UtilityThreadImpl::Send(IPC::Message* msg) {
   return ChildThread::Send(msg);
 }
 
 void UtilityThreadImpl::ReleaseProcessIfNeeded() {
-  if (!batch_mode_)
-    ChildProcess::current()->ReleaseProcess();
+  if (batch_mode_)
+    return;
+
+  // We don't need to call ChildProcess::current()->ReleaseProcess() here, and
+  // can just quit the message loop directly. This is because the unlike other
+  // kind of child processes, there's no race condition between killing utility
+  // processes. A side benefit is that it makes tests which use this code path
+  // easier to clean up.
+  base::MessageLoop::current()->Quit();
 }
 
 #if defined(OS_WIN)
 
 void UtilityThreadImpl::PreCacheFont(const LOGFONT& log_font) {
   Send(new ChildProcessHostMsg_PreCacheFont(log_font));
 }
 
 void UtilityThreadImpl::ReleaseCachedFonts() {
   Send(new ChildProcessHostMsg_ReleaseCachedFonts());
 }
 
 #endif  // OS_WIN
 
+void UtilityThreadImpl::Init() {
+  batch_mode_ = false;
+  ChildProcess::current()->AddRefProcess();
+  if (initialize_webkit_) {
+    // We can only initialize WebKit on one thread, and in single process mode
+    // we run the utility thread on separate thread. This means that if any code
+    // needs WebKit initialized in the utility process, they need to have
+    // another path to support single process mode.
+    webkit_platform_support_.reset(new WebKitPlatformSupportImpl);
+    WebKit::initialize(webkit_platform_support_.get());
+  }
+  GetContentClient()->utility()->UtilityThreadStarted();
+}
 
 bool UtilityThreadImpl::OnControlMessageReceived(const IPC::Message& msg) {
   if (GetContentClient()->utility()->OnMessageReceived(msg))
     return true;
 
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(UtilityThreadImpl, msg)
     IPC_MESSAGE_HANDLER(UtilityMsg_BatchMode_Started, OnBatchModeStarted)
     IPC_MESSAGE_HANDLER(UtilityMsg_BatchMode_Finished, OnBatchModeFinished)
 #if defined(OS_POSIX)
@@ skipping 42 matching lines @@
       Send(new UtilityHostMsg_LoadPluginFailed(i, plugin_paths[i]));
     else
       Send(new UtilityHostMsg_LoadedPlugin(i, plugin));
   }
 
   ReleaseProcessIfNeeded();
 }
 #endif
 
 }  // namespace content