Add ScopedSurfaceRequestManager

content/browser/android/scoped_surface_request_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 CONTENT_BROWSER_ANDROID_SCOPED_SURFACE_REQUEST_MANAGER_H_
+#define CONTENT_BROWSER_ANDROID_SCOPED_SURFACE_REQUEST_MANAGER_H_
+
+#include <string>
+#include <unordered_map>
+
+#include "base/macros.h"
+#include "base/memory/singleton.h"
+#include "base/unguessable_token.h"
+#include "content/common/content_export.h"
+#include "gpu/ipc/common/android/scoped_surface_request_conduit.h"
+#include "ui/gl/android/scoped_java_surface.h"
+
+namespace content {
+
+class CONTENT_EXPORT ScopedSurfaceRequestManager
+    : public gpu::ScopedSurfaceRequestConduit {
+ public:
+  static ScopedSurfaceRequestManager* GetInstance();
+
+  using ScopedSurfaceRequestCB = base::Callback<void(gl::ScopedJavaSurface)>;
+
+  // Registers a request, and returns the |request_token| that should be used to
+  // call Fulfill at a later time. The caller is responsible for unregistering
+  // the request, if it is destroyed before the request is fulfilled.
+  // It is the requester's responsibility to check the validity of the final
+  // ScopedJavaSurface (as passing an empty surface is a valid operation).
+  // Must be called on the UI thread.
+  base::UnguessableToken RegisterScopedSurfaceRequest(
+      ScopedSurfaceRequestCB request_cb);

[dcheng, 2016/09/20 06:50:35]

The original guidance was to pass callbacks as const refs. Though the updated
docs say to pass by value and use std::move() when ownership is transferred,
it's probably best to be consistent with legacy code and use const Callback& for
now until we have a clearmigration plan.

[tguilbert, 2016/09/20 20:59:19]

Good to know. Updated.

+
+  // Unregisters a request registered under |request_token| if it exists,
+  // no-ops otherwise.
+  // Must be called on the UI thread.
+  void UnregisterScopedSurfaceRequest(
+      const base::UnguessableToken& request_token);
+
+  // Unregisters and runs the request callback identified by |request_token| if
+  // one exists, no-ops otherwise.
+  // Passing an empty |surface| is a valid operation that will complete the
+  // request.
+  // Can be called from any thread. The request will be posted to the UI thread.
+  void FulfillScopedSurfaceRequest(const base::UnguessableToken& request_token,
+                                   gl::ScopedJavaSurface surface);
+
+  // Implementation of ScopedSurfaceRequestConduit.
+  // To be used in the single process case.
+  // Can be called from any thread.
+  void ForwardSurfaceTextureForSurfaceRequest(
+      const base::UnguessableToken& request_token,
+      const gl::SurfaceTexture* surface_texture) override;
+
+  void clear_requests_for_testing() { request_callbacks_.clear(); }
+
+  int request_count_for_testing() { return request_callbacks_.size(); }
+
+ private:
+  friend struct base::DefaultSingletonTraits<ScopedSurfaceRequestManager>;
+
+  // Unregisters and returns the request identified by |request_token|.
+  ScopedSurfaceRequestCB GetAndUnregisterInternal(
+      const base::UnguessableToken& request_token);
+
+  void CompleteRequestOnUiThread(const base::UnguessableToken& request_token,
+                                 gl::ScopedJavaSurface surface);
+
+  // Map used to hold references to the registered callbacks.
+  std::unordered_map<base::UnguessableToken,
+                     ScopedSurfaceRequestCB,
+                     base::UnguessableTokenHash>
+      request_callbacks_;
+
+  ScopedSurfaceRequestManager();
+  ~ScopedSurfaceRequestManager() override;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedSurfaceRequestManager);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_ANDROID_SCOPED_SURFACE_REQUEST_MANAGER_H_