[Ozone-Drm] Remove GPU lock

Workarounds to support grabbing the DRM devices as master after GPU crashes
made the GPU lock unnecessary.

BUG=none

Review URL: https://codereview.chromium.org/1141243002

Cr-Commit-Position: refs/heads/master@{#330146}

ui/ozone/platform/drm/BUILD.gn

@@ -47,8 +47,6 @@ source_set("drm_common") {
     "gpu/drm_vsync_provider.h",
     "gpu/drm_window.cc",
     "gpu/drm_window.h",
-    "gpu/gpu_lock.cc",
-    "gpu/gpu_lock.h",
     "gpu/hardware_display_controller.cc",
     "gpu/hardware_display_controller.h",
     "gpu/hardware_display_plane.cc",

ui/ozone/platform/drm/drm.gypi

@@ -69,8 +69,6 @@
         'gpu/drm_vsync_provider.h',
         'gpu/drm_window.cc',
         'gpu/drm_window.h',
-        'gpu/gpu_lock.cc',
-        'gpu/gpu_lock.h',
         'gpu/hardware_display_controller.cc',
         'gpu/hardware_display_controller.h',
         'gpu/hardware_display_plane.cc',

ui/ozone/platform/drm/gpu/gpu_lock.cc

-// Copyright 2015 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/drm/gpu/gpu_lock.h"
-
-#include <sys/file.h>
-#include <unistd.h>
-
-#include "base/logging.h"
-#include "base/posix/eintr_wrapper.h"
-
-namespace ui {
-
-namespace {
-const char kGpuLockFile[] = "/run/frecon";
-}
-
-GpuLock::GpuLock() {
-  fd_ = open(kGpuLockFile, O_RDWR);
-  if (fd_ < 0) {
-    PLOG(ERROR) << "Failed to open lock file '" << kGpuLockFile << "'";
-    return;
-  }
-
-  VLOG(1) << "Taking write lock on '" << kGpuLockFile << "'";
-  if (HANDLE_EINTR(flock(fd_, LOCK_EX)))
-    PLOG(ERROR) << "Error while trying to get lock on '" << kGpuLockFile << "'";
-
-  VLOG(1) << "Done trying to take write lock on '" << kGpuLockFile << "'";
-}
-
-GpuLock::~GpuLock() {
-  // Failed to open the lock file, so nothing to do here.
-  if (fd_ < 0)
-    return;
-
-  VLOG(1) << "Releasing write lock on '" << kGpuLockFile << "'";
-  close(fd_);
-}
-
-}  // namespace ui

ui/ozone/platform/drm/gpu/gpu_lock.h

-// Copyright 2015 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.
-
-#ifndef UI_OZONE_PLATFORM_DRM_GPU_GPU_LOCK_H_
-#define UI_OZONE_PLATFORM_DRM_GPU_GPU_LOCK_H_
-
-#include "base/macros.h"
-
-namespace ui {
-
-// Used to synchronize with Frecon and make sure the GPU process isn't trying to
-// access the DRM resources before Frecon finishes drawing.
-class GpuLock {
- public:
-  GpuLock();
-  ~GpuLock();
-
- private:
-  int fd_;
-
-  DISALLOW_COPY_AND_ASSIGN(GpuLock);
-};
-
-}  // namespace ui
-
-#endif  // UI_OZONE_PLATFORM_DRM_GPU_GPU_LOCK_H_

ui/ozone/platform/drm/ozone_platform_drm.cc

@@ -20,7 +20,6 @@
 #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_window.h"
-#include "ui/ozone/platform/drm/gpu/gpu_lock.h"
 #include "ui/ozone/platform/drm/gpu/screen_manager.h"
 #include "ui/ozone/platform/drm/host/drm_cursor.h"
 #include "ui/ozone/platform/drm/host/drm_display_host_manager.h"
@@ -88,9 +87,6 @@ class OzonePlatformDrm : public OzonePlatform {
         new DrmNativeDisplayDelegate(display_manager_.get()));
   }
   void InitializeUI() override {
-#if defined(OS_CHROMEOS)
-    gpu_lock_.reset(new GpuLock());
-#endif
     drm_device_manager_.reset(new DrmDeviceManager(
         scoped_ptr<DrmDeviceGenerator>(new DrmDeviceGenerator())));
     window_manager_.reset(new DrmWindowHostManager());
@@ -125,7 +121,6 @@ class OzonePlatformDrm : public OzonePlatform {
 
  private:
   // Objects in the "GPU" process.
-  scoped_ptr<GpuLock> gpu_lock_;
   scoped_ptr<DrmDeviceManager> drm_device_manager_;
   scoped_ptr<DrmBufferGenerator> buffer_generator_;
   scoped_ptr<ScreenManager> screen_manager_;

ui/ozone/platform/drm/ozone_platform_gbm.cc

@@ -24,7 +24,6 @@
 #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/gpu_lock.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"
@@ -170,9 +169,6 @@ class OzonePlatformGbm : public OzonePlatform {
   }
 
   void InitializeGPU() override {
-#if defined(OS_CHROMEOS)
-    gpu_lock_.reset(new GpuLock());
-#endif
     gl_api_loader_.reset(new GlApiLoader());
     drm_device_manager_.reset(new DrmDeviceManager(
         scoped_ptr<DrmDeviceGenerator>(new GbmDeviceGenerator())));
@@ -195,7 +191,6 @@ class OzonePlatformGbm : public OzonePlatform {
   scoped_ptr<GbmSurfaceFactory> surface_factory_ozone_;
 
   // Objects in the GPU process.
-  scoped_ptr<GpuLock> gpu_lock_;
   scoped_ptr<GlApiLoader> gl_api_loader_;
   scoped_ptr<DrmDeviceManager> drm_device_manager_;
   scoped_ptr<GbmBufferGenerator> buffer_generator_;