Pepper takes ownership of a mailbox before passing it to the texture layer.

gpu/ipc/service/gpu_command_buffer_stub.cc

 // 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.
 
 #include "gpu/ipc/service/gpu_command_buffer_stub.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 276 matching lines @@
   }
 
   // Always use IPC_MESSAGE_HANDLER_DELAY_REPLY for synchronous message handlers
   // here. This is so the reply can be delayed if the scheduler is unscheduled.
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(GpuCommandBufferStub, message)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(GpuCommandBufferMsg_Initialize,
                                     OnInitialize);
     IPC_MESSAGE_HANDLER_DELAY_REPLY(GpuCommandBufferMsg_SetGetBuffer,
                                     OnSetGetBuffer);
-    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_ProduceFrontBuffer,
-                        OnProduceFrontBuffer);
+    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_TakeFrontBuffer, OnTakeFrontBuffer);
+    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_ReturnFrontBuffer,
+                        OnReturnFrontBuffer);
     IPC_MESSAGE_HANDLER_DELAY_REPLY(GpuCommandBufferMsg_WaitForTokenInRange,
                                     OnWaitForTokenInRange);
     IPC_MESSAGE_HANDLER_DELAY_REPLY(GpuCommandBufferMsg_WaitForGetOffsetInRange,
                                     OnWaitForGetOffsetInRange);
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_AsyncFlush, OnAsyncFlush);
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_RegisterTransferBuffer,
                         OnRegisterTransferBuffer);
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_DestroyTransferBuffer,
                         OnDestroyTransferBuffer);
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_SignalSyncToken,
@@ skipping 391 matching lines @@
 }
 
 void GpuCommandBufferStub::OnSetGetBuffer(int32_t shm_id,
                                           IPC::Message* reply_message) {
   TRACE_EVENT0("gpu", "GpuCommandBufferStub::OnSetGetBuffer");
   if (command_buffer_)
     command_buffer_->SetGetBuffer(shm_id);
   Send(reply_message);
 }
 
-void GpuCommandBufferStub::OnProduceFrontBuffer(const Mailbox& mailbox) {
-  TRACE_EVENT0("gpu", "GpuCommandBufferStub::OnProduceFrontBuffer");
+void GpuCommandBufferStub::OnTakeFrontBuffer(const Mailbox& mailbox) {
+  TRACE_EVENT0("gpu", "GpuCommandBufferStub::OnTakeFrontBuffer");
   if (!decoder_) {
-    LOG(ERROR) << "Can't produce front buffer before initialization.";
+    LOG(ERROR) << "Can't take front buffer before initialization.";
     return;
   }
 
-  decoder_->ProduceFrontBuffer(mailbox);
+  decoder_->TakeFrontBuffer(mailbox);
+}
+
+void GpuCommandBufferStub::OnReturnFrontBuffer(const Mailbox& mailbox,
+                                               const SyncToken& sync_token,
+                                               bool is_lost) {
+  OnWaitFenceSync(sync_token.namespace_id(), sync_token.command_buffer_id(),
+                  sync_token.release_count());
+  decoder_->ReturnFrontBuffer(mailbox, is_lost);
 }
 
 void GpuCommandBufferStub::OnParseError() {
   TRACE_EVENT0("gpu", "GpuCommandBufferStub::OnParseError");
   DCHECK(command_buffer_.get());
   CommandBuffer::State state = command_buffer_->GetLastState();
   IPC::Message* msg = new GpuCommandBufferMsg_Destroyed(
       route_id_, state.context_lost_reason, state.error);
   msg->set_unblock(true);
   Send(msg);
@@ skipping 398 matching lines @@
                                                     result));
 }
 
 void GpuCommandBufferStub::SendUpdateVSyncParameters(base::TimeTicks timebase,
                                                      base::TimeDelta interval) {
   Send(new GpuCommandBufferMsg_UpdateVSyncParameters(route_id_, timebase,
                                                      interval));
 }
 
 }  // namespace gpu