Move Mus into chrome's process when running with --mus.

services/ui/gpu/gpu_main.cc

Index: services/ui/gpu/gpu_main.cc
diff --git a/services/ui/gpu/gpu_main.cc b/services/ui/gpu/gpu_main.cc
index 6b70fcf411a75ff0339fb39367ed66c56796f106..c0c1306487e281a9cfa27148766c018c08d3a50d 100644
--- a/services/ui/gpu/gpu_main.cc
+++ b/services/ui/gpu/gpu_main.cc
@@ -50,8 +50,15 @@ namespace ui {
 GpuMain::GpuMain(mojom::GpuMainRequest request)
     : gpu_thread_("GpuThread"),
       io_thread_("GpuIOThread"),
-      power_monitor_(base::MakeUnique<base::PowerMonitorDeviceSource>()),
       binding_(this) {
+  // TODO: crbug.com/609317: Remove this when Mus Window Server and GPU are
+  // split into separate processes. Until then this is necessary to be able to
+  // run Mushrome (chrome --mus) with Mus running in the browser process.
+  if (!base::PowerMonitor::Get()) {
+    power_monitor_ = base::MakeUnique<base::PowerMonitor>(
+        base::MakeUnique<base::PowerMonitorDeviceSource>());
+  }
+
   base::Thread::Options thread_options;
 
 #if defined(OS_WIN)