NotForReview: Implement zero/one-copy texture for ozone freon using Intel DRM

ui/ozone/platform/drm/host/drm_display_host_manager.cc

Index: ui/ozone/platform/drm/host/drm_display_host_manager.cc
diff --git a/ui/ozone/platform/drm/host/drm_display_host_manager.cc b/ui/ozone/platform/drm/host/drm_display_host_manager.cc
index 0305559fbe6dc5f2be5afa5377042504b7fa6f35..24846d9b5d191466d6aa18d7165336781f1fc650 100644
--- a/ui/ozone/platform/drm/host/drm_display_host_manager.cc
+++ b/ui/ozone/platform/drm/host/drm_display_host_manager.cc
@@ -23,6 +23,9 @@
 #include "ui/ozone/platform/drm/host/drm_gpu_platform_support_host.h"
 #include "ui/ozone/platform/drm/host/drm_native_display_delegate.h"
 
+#include "base/command_line.h"
+#include "ui/ozone/public/ozone_switches.h"
+
 namespace ui {
 
 namespace {
@@ -31,6 +34,7 @@ typedef base::Callback<void(const base::FilePath&, scoped_ptr<DrmDeviceHandle>)>
     OnOpenDeviceReplyCallback;
 
 const char kDefaultGraphicsCardPattern[] = "/dev/dri/card%d";
+const char kDefaultRenderNodePattern[] = "/dev/dri/renderD128";
 const char kVgemDevDriCardPath[] = "/dev/dri/";
 const char kVgemSysCardPath[] = "/sys/bus/platform/devices/vgem/drm/";
 
@@ -129,6 +133,13 @@ DrmDisplayHostManager::DrmDisplayHostManager(
     }
     drm_devices_.insert(primary_graphics_card_path_);
 
+    int fd = HANDLE_EINTR(open(kDefaultRenderNodePattern, O_RDWR | O_CLOEXEC));
+    if (fd < 0) {
+      PLOG(ERROR) << "Failed to open primary render node: "
+                  << kDefaultRenderNodePattern;
+    }
+    primary_render_node_file_.reset(fd);
+
     vgem_card_path_ = GetVgemCardPath();
     if (!vgem_card_path_.empty()) {
       int fd = HANDLE_EINTR(