Revert 17877 - Introduce a v8::Platform class that bundles embedder callbacks

include/v8-platform.h

-// Copyright 2013 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#ifndef V8_V8_PLATFORM_H_
-#define V8_V8_PLATFORM_H_
-
-#include "v8.h"
-
-namespace v8 {
-
-/**
- * A Task represents a unit of work.
- */
-class Task {
- public:
-  virtual ~Task() {}
-
-  virtual void Run() = 0;
-};
-
-/**
- * V8 Platform abstraction layer.
- *
- * The embedder has to provide an implementation of this interface before
- * initializing the rest of V8.
- */
-class Platform {
- public:
-  /**
-   * Schedules a task to be invoked on a background thread. |task_is_slow|
-   * indicates that the task will run a long time. The Platform implementation
-   * takes ownership of |task|. There is no guarantee about order of execution
-   * of tasks wrt order of scheduling, nor is there a guarantee about the
-   * thread the task will be run on.
-   */
-  virtual void CallOnBackgroundThread(Task* task, bool task_is_slow) = 0;
-
-  /**
-   * Schedules a task to be invoked on a foreground thread wrt a specific
-   * |isolate|. Tasks posted for the same isolate should be execute in order of
-   * scheduling. The definition of "foreground" is opaque to V8.
-   */
-  virtual void CallOnForegroundThread(Isolate* isolate, Task* task) = 0;
-
- protected:
-  virtual ~Platform() {}
-};
-
-}  // namespace v8
-
-#endif  // V8_V8_PLATFORM_H_