Enable asynchronous glReadPixels on Windows.

gpu/command_buffer/client/buffer_tracker.h

 // Copyright (c) 2012 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_CLIENT_BUFFER_TRACKER_H_
 #define GPU_COMMAND_BUFFER_CLIENT_BUFFER_TRACKER_H_
 
 #include <GLES2/gl2.h>
 
 #include <queue>
@@ skipping 10 matching lines @@
 
 // Tracks buffer objects for client side of command buffer.
 class GLES2_IMPL_EXPORT BufferTracker {
  public:
   class GLES2_IMPL_EXPORT Buffer {
    public:
     Buffer(GLuint id,
            unsigned int size,
            int32 shm_id,
            uint32 shm_offset,
-           void* address)
+           void* address,
+           unsigned int metadata_size)
         : id_(id),
           size_(size),
           shm_id_(shm_id),
           shm_offset_(shm_offset),
           address_(address),
+          metadata_size_(metadata_size),
           mapped_(false),
           last_usage_token_(0),
           last_async_upload_token_(0) {
     }
 
     GLenum id() const {
       return id_;
     }
 
     unsigned int size() const {
       return size_;
     }
 
     int32 shm_id() const {
       return shm_id_;
     }
 
     uint32 shm_offset() const {
       return shm_offset_;
     }
 
     void* address() const {
       return address_;
     }
 
+    unsigned int metadata_size() const {
+      return metadata_size_;
+    }
+
+    int32 metadata_shm_id() const {
+      return shm_id_;
+    }
+
+    uint32 metadata_shm_offset() const {
+      return shm_offset_ + size_;
+    }
+
+    void* metadata_address() const {
+      return static_cast<uint8*>(address_) + size_;
+    }
+
     void set_mapped(bool mapped) {
       mapped_ = mapped;
     }
 
     bool mapped() const {
       return mapped_;
     }
 
     void set_last_usage_token(int token) {
       last_usage_token_ = token;
@@ skipping 13 matching lines @@
 
    private:
     friend class BufferTracker;
     friend class BufferTrackerTest;
 
     GLuint id_;
     unsigned int size_;
     int32 shm_id_;
     uint32 shm_offset_;
     void* address_;
+    unsigned int metadata_size_;
     bool mapped_;
     int32 last_usage_token_;
     GLuint last_async_upload_token_;
   };
 
   BufferTracker(MappedMemoryManager* manager);
   ~BufferTracker();
 
-  Buffer* CreateBuffer(GLuint id, GLsizeiptr size);
+  Buffer* CreateBuffer(GLuint id, GLsizeiptr size, GLsizeiptr metadata_size);
   Buffer* GetBuffer(GLuint id);
   void RemoveBuffer(GLuint id);
 
   // Frees the block of memory associated with buffer, pending the passage
   // of a token.
   void FreePendingToken(Buffer* buffer, int32 token);
   void Unmanage(Buffer* buffer);
   void Free(Buffer* buffer);
 
  private:
   typedef base::hash_map<GLuint, Buffer*> BufferMap;
 
   MappedMemoryManager* mapped_memory_;
   BufferMap buffers_;
 
   DISALLOW_COPY_AND_ASSIGN(BufferTracker);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_BUFFER_TRACKER_H_