Switch DRM platform to using a separate thread

ui/ozone/platform/drm/ozone_platform_gbm.cc

Index: ui/ozone/platform/drm/ozone_platform_gbm.cc
diff --git a/ui/ozone/platform/drm/ozone_platform_gbm.cc b/ui/ozone/platform/drm/ozone_platform_gbm.cc
index e321daeff227ddfe6a0127f8e870783e4c43d989..a8a97c4daa5b046933359fdc2fbc888c94b5cdde 100644
--- a/ui/ozone/platform/drm/ozone_platform_gbm.cc
+++ b/ui/ozone/platform/drm/ozone_platform_gbm.cc
@@ -20,10 +20,13 @@
 #include "ui/ozone/platform/drm/gpu/drm_device_manager.h"
 #include "ui/ozone/platform/drm/gpu/drm_gpu_display_manager.h"
 #include "ui/ozone/platform/drm/gpu/drm_gpu_platform_support.h"
+#include "ui/ozone/platform/drm/gpu/drm_gpu_platform_support_proxy.h"
+#include "ui/ozone/platform/drm/gpu/drm_thread.h"
 #include "ui/ozone/platform/drm/gpu/gbm_buffer.h"
 #include "ui/ozone/platform/drm/gpu/gbm_device.h"
 #include "ui/ozone/platform/drm/gpu/gbm_surface.h"
 #include "ui/ozone/platform/drm/gpu/gbm_surface_factory.h"
+#include "ui/ozone/platform/drm/gpu/proxy_helpers.h"
 #include "ui/ozone/platform/drm/gpu/scanout_buffer.h"
 #include "ui/ozone/platform/drm/gpu/screen_manager.h"
 #include "ui/ozone/platform/drm/host/drm_cursor.h"
@@ -112,6 +115,36 @@ class GbmDeviceGenerator : public DrmDeviceGenerator {
   DISALLOW_COPY_AND_ASSIGN(GbmDeviceGenerator);
 };
 
+class GbmThread : public DrmThread {
+ public:
+  GbmThread(bool use_surfaceless) : use_surfaceless_(use_surfaceless) {}
+  ~GbmThread() override {}
+
+  // DrmThread:
+  void Init() override {
+    bool use_atomic = false;
+#if defined(USE_DRM_ATOMIC)
+    use_atomic = true;
+#endif
+
+    device_manager_.reset(new DrmDeviceManager(
+        make_scoped_ptr(new GbmDeviceGenerator(use_atomic))));
+    buffer_generator_.reset(new GbmBufferGenerator());
+    screen_manager_.reset(new ScreenManager(buffer_generator_.get()));
+
+    scoped_ptr<DrmGpuDisplayManager> display_manager(
+        new DrmGpuDisplayManager(screen_manager_.get(), device_manager_.get()));
+    gpu_platform_support_.reset(new DrmGpuPlatformSupport(
+        device_manager_.get(), screen_manager_.get(), buffer_generator_.get(),
+        display_manager.Pass()));
+  }
+
+ private:
+  bool use_surfaceless_;
+
+  DISALLOW_COPY_AND_ASSIGN(GbmThread);
+};
+
 class OzonePlatformGbm : public OzonePlatform {
  public:
   OzonePlatformGbm(bool use_surfaceless) : use_surfaceless_(use_surfaceless) {}
@@ -119,7 +152,7 @@ class OzonePlatformGbm : public OzonePlatform {
 
   // OzonePlatform:
   ui::SurfaceFactoryOzone* GetSurfaceFactoryOzone() override {
-    return surface_factory_ozone_.get();
+    return surface_factory_.get();
   }
   OverlayManagerOzone* GetOverlayManager() override {
     return overlay_manager_.get();
@@ -131,6 +164,9 @@ class OzonePlatformGbm : public OzonePlatform {
     return event_factory_ozone_->input_controller();
   }
   GpuPlatformSupport* GetGpuPlatformSupport() override {
+    if (!gpu_platform_support_)
+      InitializeDrmThread();
+
     return gpu_platform_support_.get();
   }
   GpuPlatformSupportHost* GetGpuPlatformSupportHost() override {
@@ -187,36 +223,27 @@ class OzonePlatformGbm : public OzonePlatform {
   }
 
   void InitializeGPU() override {
-    bool use_atomic = false;
-#if defined(USE_DRM_ATOMIC)
-    use_atomic = true;
-#endif
     gl_api_loader_.reset(new GlApiLoader());
-    drm_device_manager_.reset(new DrmDeviceManager(
-        scoped_ptr<DrmDeviceGenerator>(new GbmDeviceGenerator(use_atomic))));
-    buffer_generator_.reset(new GbmBufferGenerator());
-    screen_manager_.reset(new ScreenManager(buffer_generator_.get()));
-    surface_factory_ozone_.reset(new GbmSurfaceFactory(use_surfaceless_));
-    surface_factory_ozone_->InitializeGpu(drm_device_manager_.get(),
-                                          screen_manager_.get());
-    scoped_ptr<DrmGpuDisplayManager> display_manager(new DrmGpuDisplayManager(
-        screen_manager_.get(), drm_device_manager_.get()));
-    gpu_platform_support_.reset(new DrmGpuPlatformSupport(
-        drm_device_manager_.get(), screen_manager_.get(),
-        buffer_generator_.get(), display_manager.Pass()));
+    drm_thread_.reset(new GbmThread(use_surfaceless_));
+
+    surface_factory_.reset(
+        new GbmSurfaceFactory(use_surfaceless_, drm_thread_.get()));
   }
 
  private:
+  void InitializeDrmThread() {
+    drm_thread_->Start();
+    gpu_platform_support_ = drm_thread_->CreateGpuPlatformSupportProxy();
+  }
+
   // Objects in both processes.
   bool use_surfaceless_;
 
   // Objects in the GPU process.
-  scoped_ptr<GbmSurfaceFactory> surface_factory_ozone_;
+  scoped_ptr<DrmThread> drm_thread_;
   scoped_ptr<GlApiLoader> gl_api_loader_;
-  scoped_ptr<DrmDeviceManager> drm_device_manager_;
-  scoped_ptr<GbmBufferGenerator> buffer_generator_;
-  scoped_ptr<ScreenManager> screen_manager_;
-  scoped_ptr<DrmGpuPlatformSupport> gpu_platform_support_;
+  scoped_ptr<GbmSurfaceFactory> surface_factory_;
+  scoped_ptr<DrmGpuPlatformSupportProxy> gpu_platform_support_;
 
   // Objects in the Browser process.
   scoped_ptr<DeviceManager> device_manager_;