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

ui/ozone/public/native_pixmap_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_NATIVE_PIXMAP_CLIENT_H_
+#define UI_OZONE_PUBLIC_NATIVE_PIXMAP_CLIENT_H_
+
+#include "ui/ozone/ozone_export.h"
+#include "ui/ozone/public/surface_factory_ozone.h"
+
+namespace ui {
+
+// The Ozone interface allows external implementations to hook into Chromium to
+// provide the handle of a system specific surface implementation for Browser
+// and Render process.
+class OZONE_EXPORT NativePixmapClient {

[reveman, 2015/06/05 20:26:07]

NativePixmapClient sounds like we'd have one of these instances per NativePixmap
but that's not the case.

This is similar to the IOSurfaceManager interface on MacOS and the
SurfaceTextureManager interface on Android. Would it make sense to call this
NativePixmapManager for consistency?

[spang, 2015/06/05 22:21:23]

That sounds good to me.

[dshwang, 2015/06/08 11:15:14]

Done.

+ public:
+  NativePixmapClient();
+  virtual ~NativePixmapClient();
+
+  // Initializes the resources necessary.
+  static void InitializeIfNeeded();
+
+  static NativePixmapClient* GetInstance();
+
+  struct Configuration {
+    SurfaceFactoryOzone::BufferFormat format;
+    SurfaceFactoryOzone::BufferUsage usage;
+  };
+
+  // Gets supported format/usage configurations.
+  virtual std::vector<Configuration> GetSupportedNativePixmapConfigurations()

[spang, 2015/06/05 19:21:54]

Is this used from the renderer? (Does it need to move?)

[dshwang, 2015/06/08 11:15:14]

Currently it's used by browser process. Renderer will use it soon.
In addition, each platform (e.g. gbm, drm) supports different configuration.

+      const;

[reveman, 2015/06/05 20:26:07]

can this be pure virtual?

[dshwang, 2015/06/08 11:15:14]

Done.

+
+ private:
+  static void CreateInstance();
+  virtual void Initialize();
+
+  DISALLOW_COPY_AND_ASSIGN(NativePixmapClient);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PUBLIC_NATIVE_PIXMAP_CLIENT_H_