DialogSurfaceManager implementation.

media/base/android/dialog_surface_manager.h

+// Copyright 2016 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 MEDIA_BASE_ANDROID_DIALOG_SURFACE_MANAGER_H_
+#define MEDIA_BASE_ANDROID_DIALOG_SURFACE_MANAGER_H_
+
+#include <jni.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <set>
+#include <string>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/process/process_handle.h"
+#include "base/time/time.h"
+#include "media/base/android/dialog_surface.h"
+#include "media/base/media_export.h"
+#include "ui/gfx/geometry/point.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace media {
+
+// This class implements the C++ wrapper around the java DialogSurfaceManager.
+// Typical usage is:
+//
+// callback = something that is a DialogSurface::Callback;
+// unique_ptr<DialogSurface> surface = DialogSurfaceManager::GetPointer()->
+//                                        CreateSurface(callback);
+// (wait for callback)
+// surface->GetSurface()
+// if (i_want_to_change_the_layout_)
+//   surface->ScheduleLayout(new_position_and_size);
+class MEDIA_EXPORT DialogSurfaceManager {
+ public:
+  // Return singleton manager instance.
+  static DialogSurfaceManager* Get();
+
+  using Config = DialogSurface::Config;
+
+  // Create a surface for renderer frame owned by renderer |pid|, and id
+  // |render_frame_id|.  May return null.
+  std::unique_ptr<DialogSurface> CreateSurface(
+      base::ProcessHandle pid,
+      int render_frame_id,
+      const Config& config,
+      const DialogSurface::Callback& cb);
+
+ protected:

[boliu, 2017/01/04 01:48:44]

why protected? is there a subclass? (in which case destructor needs to be
virtual)

[liberato (no reviews please), 2017/01/11 22:17:57]

no subclass.  private, done.

+  DialogSurfaceManager();
+  ~DialogSurfaceManager();
+
+ private:
+  friend struct base::DefaultLazyInstanceTraits<DialogSurfaceManager>;
+
+  // Java DialogSurfaceManagerWrapper instance.
+  base::android::ScopedJavaGlobalRef<jobject> j_wrapped_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(DialogSurfaceManager);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_ANDROID_DIALOG_SURFACE_MANAGER_H_