Intiialize AudioManager and related class lazily

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright 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 170 matching lines @@
 #include "ui/gl/gl_switches.h"
 #include "ui/gl/gpu_switching_manager.h"
 #include "ui/native_theme/native_theme_switches.h"
 
 #if defined(OS_ANDROID)
 #include "content/browser/android/child_process_launcher_android.h"
 #include "content/browser/media/android/browser_demuxer_android.h"
 #include "content/browser/mojo/service_registrar_android.h"
 #include "content/browser/screen_orientation/screen_orientation_message_filter_android.h"
 #include "ipc/ipc_sync_channel.h"
+#include "media/audio/android/audio_manager_android.h"
 #endif
 
 #if defined(OS_WIN)
 #include "base/win/scoped_com_initializer.h"
 #include "base/win/windows_version.h"
 #include "content/browser/renderer_host/dwrite_font_proxy_message_filter_win.h"
 #include "content/common/font_cache_dispatcher_win.h"
 #include "content/common/sandbox_win.h"
 #include "sandbox/win/src/sandbox_policy.h"
 #include "ui/display/win/dpi.h"
@@ skipping 393 matching lines @@
   // render process. This ensures that when a test is being run in one of the
   // single process modes, the global attachment broker is the privileged
   // attachment broker, rather than an unprivileged attachment broker.
 #if defined(OS_MACOSX)
   IPC::AttachmentBrokerPrivileged::CreateBrokerIfNeeded(
       MachBroker::GetInstance());
 #else
   IPC::AttachmentBrokerPrivileged::CreateBrokerIfNeeded();
 #endif  // defined(OS_MACOSX)
 #endif  // USE_ATTACHMENT_BROKER
+
+#if !defined(OS_MACOSX)
+  // On Mac audio thread is the UI thread, a hang monitor is not
+  // necessary or recommended.
+  media::AudioManager::StartHangMonitor(

[no sievers, 2016/06/21 23:57:22]

Doesn't this blow up if being called repeatedly?

Maybe just needs a 'if (!BrowserMainLoop::GetInstance()->audio_manager())'?

[qinmin, 2016/06/22 00:15:56]

That doesn't work in ChromeOS case though since audio_manager() is already
created before renderer process are created.
I changed the AudioManagerHelper::StartHangTimer() to abort early if this is
already called.

+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
+#endif  // !defined(OS_MACOSX)
+#if defined(OS_ANDROID)
+  static_cast<media::AudioManagerAndroid*> (
+      media::AudioManager::Get())->InitializeIfNeeded();
+#endif  // defined(OS_ANDROID)
 }
 
 // static
 void RenderProcessHostImpl::ShutDownInProcessRenderer() {
   DCHECK(g_run_renderer_in_process_);
 
   switch (g_all_hosts.Pointer()->size()) {
     case 0:
       return;
     case 1: {
@@ skipping 2197 matching lines @@
   LOG(ERROR) << "Terminating render process for bad Mojo message: " << error;
 
   // The ReceivedBadMessage call below will trigger a DumpWithoutCrashing. Alias
   // enough information here so that we can determine what the bad message was.
   base::debug::Alias(&error);
   bad_message::ReceivedBadMessage(process.get(),
                                   bad_message::RPH_MOJO_PROCESS_ERROR);
 }
 
 }  // namespace content