ozone: ClientPixmapManager passes VGEM fd from browser to renderer.

content/child/child_client_native_pixmap_factory_message_filter_ozone.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 "content/child/child_client_native_pixmap_factory_message_filter_ozone.h"
+
+#include "base/files/scoped_file.h"
+#include "content/child/child_client_native_pixmap_factory_ozone.h"
+#include "content/common/gpu/client_native_pixmap_factory_ozone_messages.h"
+#include "ipc/ipc_message_macros.h"
+
+namespace content {
+
+ChildClientNativePixmapFactoryMessageFilter::
+    ChildClientNativePixmapFactoryMessageFilter() {}
+
+ChildClientNativePixmapFactoryMessageFilter::
+    ~ChildClientNativePixmapFactoryMessageFilter() {}
+
+void ChildClientNativePixmapFactoryMessageFilter::OnSetVirtualDevice(
+    const base::FileDescriptor& virtual_device) {
+  if (!ui::ClientNativePixmapFactory::GetInstance()) {
+    ChildClientNativePixmapFactory::GetInstance()->Initialize(virtual_device);
+    ui::ClientNativePixmapFactory::SetInstance(
+        ChildClientNativePixmapFactory::GetInstance());

[reveman, 2015/08/13 18:05:28]

How do we make sure this happens before the renderer tries to allocate a
GpuMemoryBuffer? If you follow the IOSurface token pattern as suggested below it
becomes easier to see what the problem is and what needs to be done to fix it.

[dshwang, 2015/08/14 12:40:03]

Ok, now Renderer waits for vgem fd on importing NativePixmap like IOSurface
pattern.

+  } else {
+    // Many child threads can live in the same process. e.g. --single-process
+    if (virtual_device.auto_close) {
+      base::ScopedFD closing_fd(virtual_device.fd);
+    }
+  }
+}
+
+bool ChildClientNativePixmapFactoryMessageFilter::OnMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(ChildClientNativePixmapFactoryMessageFilter, message)
+    IPC_MESSAGE_HANDLER(ChildClientNativePixmapFactoryMsg_SetVirtualDevice,
+                        OnSetVirtualDevice)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+}  // namespace content