ui: Add libsync GLFence implementation.

ui/gfx/shared_event.cc

 // Copyright 2016 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 "base/atomicops.h"
 #include "base/macros.h"
 #include "base/process/memory.h"
 #include "base/time/time.h"
 #include "ui/gfx/gfx_export.h"
 #include "ui/gfx/shared_event.h"
@@ skipping 30 matching lines @@
 SharedEventHandle SharedEvent::CreateForProcess(base::ProcessHandle process) {
   base::SharedMemory shared_memory;
   if (!shared_memory.CreateAnonymous(kSharedMemorySize))
     return SharedEventHandle();
   base::SharedMemoryHandle handle;
   shared_memory.GiveToProcess(process, &handle);
   return handle;
 }
 
 // static
+bool SharedEvent::IsHandleValid(const SharedEventHandle& handle) {
+  return base::SharedMemory::IsHandleValid(handle);
+}
+
+// static
 SharedEventHandle SharedEvent::DuplicateHandle(
     const SharedEventHandle& handle) {
   return base::SharedMemory::DuplicateHandle(handle);
 }
 
 void SharedEvent::Reset() {
   // Change state to un-signaled iff event is currently in signaled state.
   base::subtle::NoBarrier_CompareAndSwap(uaddr(), SIGNALED, NOT_SIGNALED);
 }
 
@@ skipping 50 matching lines @@
 
 SharedEventHandle SharedEvent::GetHandle() const {
   return shared_memory_.handle();
 }
 
 void SharedEvent::Close() {
   shared_memory_.Close();
 }
 
 }  // namespace gfx