ui: Add libsync GLFence implementation.

content/browser/gpu/browser_gpu_memory_buffer_manager.cc

Index: content/browser/gpu/browser_gpu_memory_buffer_manager.cc
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
index ad0647281a3ebb559336e7a09098857dcf126319..61ab8f947d26583f7d8fc94fc5a9d1fc153ebbad 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
@@ -21,6 +21,7 @@
 #include "content/public/common/content_switches.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "gpu/ipc/client/gpu_fence_impl.h"
+#include "gpu/ipc/client/gpu_fence_impl_shared_event.h"
 #include "gpu/ipc/client/gpu_memory_buffer_impl.h"
 #include "gpu/ipc/client/gpu_memory_buffer_impl_shared_memory.h"
 #include "gpu/ipc/common/gpu_memory_buffer_support.h"
@@ -28,6 +29,10 @@
 #include "ui/gfx/gpu_memory_buffer_tracing.h"
 #include "ui/gl/gl_switches.h"
 
+#if defined(OS_LINUX)
+#include "gpu/ipc/client/gpu_fence_impl_libsync.h"
+#endif
+
 namespace content {
 namespace {
 
@@ -306,13 +311,17 @@ void BrowserGpuMemoryBufferManager::SetDestructionSyncToken(
 }
 
 std::unique_ptr<gfx::GpuFence> BrowserGpuMemoryBufferManager::CreateGpuFence() {
-  std::unique_ptr<gpu::GpuFenceImpl> fence(new gpu::GpuFenceImpl);
+  std::unique_ptr<gpu::GpuFenceImpl> fence(new gpu::GpuFenceImplSharedEvent);
   return std::move(fence);
 }
 
 std::unique_ptr<gfx::GpuFence>
 BrowserGpuMemoryBufferManager::CreateGpuFenceFromHandle(
     const gfx::GpuFenceHandle& handle) {
+#if defined(OS_LINUX)
+  if (handle.fd.fd >= 0)
+    return base::MakeUnique<gpu::GpuFenceImplLibsync>(handle.fd);
+#endif
   return nullptr;
 }