Add gfx::GpuMemoryBuffer::shared_memory_handle()

gpu/ipc/client/gpu_memory_buffer_impl_shared_memory.cc

Index: gpu/ipc/client/gpu_memory_buffer_impl_shared_memory.cc
diff --git a/gpu/ipc/client/gpu_memory_buffer_impl_shared_memory.cc b/gpu/ipc/client/gpu_memory_buffer_impl_shared_memory.cc
index 54423d51ceef266fe271be741f8bfa1725b01c56..add9aaec59babcc8da1370e464925a23a251db78 100644
--- a/gpu/ipc/client/gpu_memory_buffer_impl_shared_memory.cc
+++ b/gpu/ipc/client/gpu_memory_buffer_impl_shared_memory.cc
@@ -166,6 +166,13 @@ base::Closure GpuMemoryBufferImplSharedMemory::AllocateForTesting(
   return base::Bind(&base::DoNothing);
 }
 
+base::SharedMemoryHandle GpuMemoryBufferImplSharedMemory::shared_memory_handle()
+    const {
+  if (!shared_memory_)
+    return base::SharedMemoryHandle();
+  return shared_memory_->handle();
+}
+
 bool GpuMemoryBufferImplSharedMemory::Map() {
   DCHECK(!mapped_);