Set up content in-process main threads via factory

This code was previously #ifdef'd out based on CHROME_MULTIPLE_DLL. This works
for chrome, but not for test targets which link content_browser. content_browser
needs to not link against child-only targets (as they'll cause linking blink
into the browser dll).

Instead of having utility_process_host_impl, et al. own the in-process
implementation, use a factory to create them that's installed in test code, and
in chrome for supporting --single-process.

At the same time, remove the global CHROME_MULTIPLE_DLL define and localize it
to chrome_exe.gypi because it's too easy to use incorrectly.

TBR=darin
R=piman@chromium.org,jam@chromium.org
BUG=237249

Review URL: https://chromiumcodereview.appspot.com/23235002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@217968 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 90 insertions, 0 deletions

diff --git a/content/utility/utility_main_thread.cc b/content/utility/utility_main_thread.cc
new file mode 100644
index 0000000..7d97399
--- /dev/null
+++ b/content/utility/utility_main_thread.cc
@@ -0,0 +1,50 @@
+// Copyright 2013 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_main_thread.h"
+
+#include "content/child/child_process.h"
+#include "content/utility/utility_thread_impl.h"
+
+namespace content {
+
+// We want to ensure there's only one utility thread running at a time, as there
+// are many globals used in the utility process.
+static base::LazyInstance<base::Lock> g_one_utility_thread_lock;
+
+UtilityMainThread::UtilityMainThread(const std::string& channel_id)
+    : Thread("Chrome_InProcUtilityThread"), channel_id_(channel_id) {
+}
+
+UtilityMainThread::~UtilityMainThread() {
+  Stop();
+}
+
+void UtilityMainThread::Init() {
+  // We need to return right away or else the main thread that started us will
+  // hang.
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE,
+      base::Bind(&UtilityMainThread::InitInternal, base::Unretained(this)));
+}
+
+void UtilityMainThread::CleanUp() {
+  child_process_.reset();
+
+  // See comment in RendererMainThread.
+  SetThreadWasQuitProperly(true);
+  g_one_utility_thread_lock.Get().Release();
+}
+
+void UtilityMainThread::InitInternal() {
+  g_one_utility_thread_lock.Get().Acquire();
+  child_process_.reset(new ChildProcess());
+  child_process_->set_main_thread(new UtilityThreadImpl(channel_id_));
+}
+
+base::Thread* CreateUtilityMainThread(const std::string& channel_id) {
+  return new UtilityMainThread(channel_id);
+}
+
+}  // namespace content
diff --git a/content/utility/utility_main_thread.h b/content/utility/utility_main_thread.h
new file mode 100644
index 0000000..43e22b7
--- /dev/null
+++ b/content/utility/utility_main_thread.h
@@ -0,0 +1,40 @@
+// Copyright 2013 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_UTILITY_UTILITY_MAIN_THREAD_H_
+#define CONTENT_UTILITY_UTILITY_MAIN_THREAD_H_
+
+#include <string>
+
+#include "base/threading/thread.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class ChildProcess;
+
+class UtilityMainThread : public base::Thread {
+ public:
+  UtilityMainThread(const std::string& channel_id);
+  virtual ~UtilityMainThread();
+ private:
+
+  // base::Thread implementation:
+  virtual void Init() OVERRIDE;
+  virtual void CleanUp() OVERRIDE;
+
+  void InitInternal();
+
+  std::string channel_id_;
+  scoped_ptr<ChildProcess> child_process_;
+
+  DISALLOW_COPY_AND_ASSIGN(UtilityMainThread);
+};
+
+CONTENT_EXPORT base::Thread* CreateUtilityMainThread(
+    const std::string& channel_id);
+
+}  // namespace content
+
+#endif  // CONTENT_UTILITY_UTILITY_MAIN_THREAD_H_