Expedite discovery of primary DRM device.

ui/ozone/public/gpu_platform_support_host.h

Index: ui/ozone/public/gpu_platform_support_host.h
diff --git a/ui/ozone/public/gpu_platform_support_host.h b/ui/ozone/public/gpu_platform_support_host.h
index b15b13117c06fa2c8f3383c0272f47726df45726..6a1ef2277a15d75217d7dac6ca06eb4e43e91bf5 100644
--- a/ui/ozone/public/gpu_platform_support_host.h
+++ b/ui/ozone/public/gpu_platform_support_host.h
@@ -27,13 +27,19 @@ class OZONE_BASE_EXPORT GpuPlatformSupportHost : public IPC::Listener {
   GpuPlatformSupportHost();
   ~GpuPlatformSupportHost() override;
 
-  // Called when the GPU process is spun up & channel established.
-  virtual void OnChannelEstablished(
+  // Called when the GPU process is spun up.
+  // This is called from browser IO thread.
+  virtual void OnGpuProcessLaunched(
       int host_id,
       scoped_refptr<base::SingleThreadTaskRunner> send_runner,
       const base::Callback<void(IPC::Message*)>& sender) = 0;
 
+  // Called when the channel is established.
+  // This is called from browser UI thread.
+  virtual void OnChannelEstablished() = 0;
+
   // Called when the GPU process is destroyed.
+  // This is called from browser UI thread.
   virtual void OnChannelDestroyed(int host_id) = 0;
 };