Update from chromium https://crrev.com/301315

gpu/command_buffer/service/mailbox_manager_sync.h

+// Copyright 2014 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 GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_SYNC_H_
+#define GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_SYNC_H_
+
+#include <map>
+#include <utility>
+
+#include "base/lazy_instance.h"
+#include "base/memory/ref_counted.h"
+#include "gpu/command_buffer/common/constants.h"
+#include "gpu/command_buffer/common/mailbox.h"
+#include "gpu/command_buffer/service/mailbox_manager.h"
+#include "gpu/command_buffer/service/texture_definition.h"
+#include "gpu/gpu_export.h"
+
+namespace gpu {
+namespace gles2 {
+
+class Texture;
+class TextureManager;
+
+// Manages resources scoped beyond the context or context group level
+// and across threads and driver level share groups by synchronizing
+// texture state.
+class GPU_EXPORT MailboxManagerSync : public MailboxManager {
+ public:
+  MailboxManagerSync();
+
+  // MailboxManager implementation:
+  Texture* ConsumeTexture(const Mailbox& mailbox) override;
+  void ProduceTexture(const Mailbox& mailbox, Texture* texture) override;
+  bool UsesSync() override;
+  void PushTextureUpdates(uint32 sync_point) override;
+  void PullTextureUpdates(uint32 sync_point) override;
+  void TextureDeleted(Texture* texture) override;
+
+ private:
+  friend class base::RefCounted<MailboxManager>;
+
+  ~MailboxManagerSync() override;
+
+  class TextureGroup : public base::RefCounted<TextureGroup> {
+   public:
+    static TextureGroup* CreateFromTexture(const Mailbox& name,
+                                           MailboxManagerSync* manager,
+                                           Texture* texture);
+    static TextureGroup* FromName(const Mailbox& name);
+
+    void AddName(const Mailbox& name);
+    void RemoveName(const Mailbox& name);
+
+    void AddTexture(MailboxManagerSync* manager, Texture* texture);
+    // Returns true if there are other textures left in the group after removal.
+    bool RemoveTexture(MailboxManagerSync* manager, Texture* texture);
+    Texture* FindTexture(MailboxManagerSync* manager);
+
+    const TextureDefinition& GetDefinition() { return definition_; }
+    void SetDefinition(TextureDefinition definition) {
+      definition_ = definition;
+    }
+
+   private:
+    friend class base::RefCounted<TextureGroup>;
+    TextureGroup();
+    ~TextureGroup();
+
+    typedef std::vector<std::pair<MailboxManagerSync*, Texture*>> TextureList;
+    std::vector<Mailbox> names_;
+    TextureList textures_;
+    TextureDefinition definition_;
+
+    typedef std::map<Mailbox, scoped_refptr<TextureGroup>>
+        MailboxToGroupMap;
+    static base::LazyInstance<MailboxToGroupMap> mailbox_to_group_;
+  };
+
+  struct TextureGroupRef {
+    TextureGroupRef(unsigned version, TextureGroup* group);
+    ~TextureGroupRef();
+    unsigned version;
+    scoped_refptr<TextureGroup> group;
+  };
+  static void UpdateDefinitionLocked(Texture* texture,
+                                     TextureGroupRef* group_ref);
+
+  typedef std::map<Texture*, TextureGroupRef> TextureToGroupMap;
+  TextureToGroupMap texture_to_group_;
+
+  DISALLOW_COPY_AND_ASSIGN(MailboxManagerSync);
+};
+
+}  // namespage gles2
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_SYNC_H_
+