ozone: Introduce ClientPixmap and ClientPixmapFactory for non-GPU processes.

ui/ozone/public/ozone_client.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_PUBLIC_OZONE_CLIENT_H_
+#define UI_OZONE_PUBLIC_OZONE_CLIENT_H_
+
+#include "ui/ozone/ozone_export.h"
+
+namespace ui {
+
+class SurfaceClientFactoryOzone;
+
+// Base class for Ozone client implementations. Render process and UI process
+// use OzoneClient instead of OzonePlatform to access Ozone specific
+// features. e.g. share a surface created by GPU process
+//
+// UI process uses both OzoneClient and OzonePlatform but the purpose is
+// different. UI process initializes subsystems (e.g. events, surface) via
+// OzonePlatform, while OzoneClient is used for ozone client purpose.
+// (e.g. surface sharing)
+//
+// Each Ozone platforms override this class and implement the virtual
+// GetFooFactoryOzone() methods to provide implementations of the
+// various ozone interfaces.
+//
+// A platform is free to use different implementations of each
+// interface depending on the context. You can, for example, create
+// different objects depending on the underlying hardware, command
+// line flags, or whatever is appropriate for the platform.
+class OZONE_EXPORT OzoneClient {
+ public:
+  OzoneClient();
+  virtual ~OzoneClient();
+
+  // Initializes the resources necessary for the UI process.
+  static void InitializeForUI();
+
+  // Initializes the resources necessary for the Render process.
+  static void InitializeForRenderer();

[spang, 2015/06/01 22:46:41]

Why are these functions separate but do the same thing?

I wasn't suggesting to copy the existing pattern of having a singleton with
multiple initializers depending on process. This is what I want to avoid.

If the object has only one purpose it doesn't matter which process we're in. The
processes that want one will create one, and the processes that don't need one
won't.

I think we should just remove OzoneClient, and do something like:

// ui/ozone/public/native_pixmap_client.h
class NativePixmapClient {
public:
  static scoped_ptr<NativePixmapClient> Create();

  bool Initialize( /* TBD args - need a way to pass in vgem fd */ );
 
  static scoped_refptr<NativePixmap> ImportNativePixmap(
      base::FileDescriptor handle,
      const gfx::Size& size,
      BufferFormat format);
};

// ui/ozone/public/native_pixmap_client.cc
scoped_ptr<NativePixmapClient> NativePixmapClient::Create() {
  return PlatformObject<NativePixmapClient>::Create();
}

The renderer would make one of these and use it to import buffers. We need to
discuss how to initialize it with the vgem fd obviously.

I probably got some of the details wrong, but does this seem doable?

[dshwang, 2015/06/03 14:11:51]

Sure, I comments future plan in NativePixmapClientGbm::Initialize()
Nice idea!

+
+  static OzoneClient* GetInstance();
+
+  // Factory getters to override in subclasses. The returned objects will be
+  // injected into the appropriate layer at startup. Subclasses should not
+  // inject these objects themselves. Ownership is retained by OzoneClient.
+  virtual SurfaceClientFactoryOzone* GetSurfaceClientFactoryOzone() = 0;
+
+ private:
+  virtual void InitializeUI() = 0;
+  virtual void InitializeRenderer() = 0;
+
+  static void CreateInstance();
+
+  DISALLOW_COPY_AND_ASSIGN(OzoneClient);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PUBLIC_OZONE_CLIENT_H_