[Ozone-Dri] Gracefully handle DRM devices with no resources

ui/ozone/platform/dri/dri_wrapper.cc

 // Copyright 2014 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.
 
 #include "ui/ozone/platform/dri/dri_wrapper.h"
 
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #include <xf86drm.h>
@@ skipping 145 matching lines @@
 
 DriWrapper::DriWrapper(const base::FilePath& device_path, base::File file)
     : device_path_(device_path), file_(file.Pass()) {
 }
 
 DriWrapper::~DriWrapper() {
   if (watcher_)
     watcher_->Shutdown();
 }
 
-void DriWrapper::Initialize() {
+bool DriWrapper::Initialize() {
   plane_manager_.reset(new HardwareDisplayPlaneManagerLegacy());
-  if (!plane_manager_->Initialize(this))
-    LOG(ERROR) << "Failed to initialize the plane manager";
+  if (!plane_manager_->Initialize(this)) {
+    LOG(ERROR) << "Failed to initialize the plane manager for "
+               << device_path_.value();
+    return false;

[alexst (slow to review), 2015/02/23 21:46:32]

Should reset the plane manager here since it's in an invalid state? I know we
clean up the whole wrapper later, but I prefer we don't leave partially
initialized state since it's unclear from here that failed init means deletion
later.

[dnicoara, 2015/02/23 21:49:10]

Done.

+  }
+
+  return true;
 }
 
 void DriWrapper::InitializeTaskRunner(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner) {
   DCHECK(!task_runner_);
   task_runner_ = task_runner;
   watcher_ = new IOWatcher(file_.GetPlatformFile(), task_runner_);
 }
 
 ScopedDrmCrtcPtr DriWrapper::GetCrtc(uint32_t crtc_id) {
@@ skipping 226 matching lines @@
   DCHECK(file_.IsValid());
   return (drmSetMaster(file_.GetPlatformFile()) == 0);
 }
 
 bool DriWrapper::DropMaster() {
   DCHECK(file_.IsValid());
   return (drmDropMaster(file_.GetPlatformFile()) == 0);
 }
 
 }  // namespace ui