[Reland 1] Pepper takes ownership of a mailbox before passing it to the texture layer.

gpu/ipc/common/gpu_messages.h

Index: gpu/ipc/common/gpu_messages.h
diff --git a/gpu/ipc/common/gpu_messages.h b/gpu/ipc/common/gpu_messages.h
index 85800540230c2c5ca35fc271aee41c612c96f2b8..3d658a5672f293304dcc54bc6ffd3bafa85aad12 100644
--- a/gpu/ipc/common/gpu_messages.h
+++ b/gpu/ipc/common/gpu_messages.h
@@ -138,11 +138,18 @@ IPC_SYNC_MESSAGE_ROUTED1_2(GpuCommandBufferMsg_Initialize,
 IPC_SYNC_MESSAGE_ROUTED1_0(GpuCommandBufferMsg_SetGetBuffer,
                            int32_t /* shm_id */)
 
-// Produces the front buffer into a mailbox. This allows another context to draw
+// Takes the front buffer into a mailbox. This allows another context to draw
 // the output of this context.
-IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_ProduceFrontBuffer,
+IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_TakeFrontBuffer,
                     gpu::Mailbox /* mailbox */)
 
+// Returns a front buffer taken with GpuCommandBufferMsg_TakeFrontBuffer. This
+// allows it to be reused.
+IPC_MESSAGE_ROUTED3(GpuCommandBufferMsg_ReturnFrontBuffer,
+                    gpu::Mailbox /* mailbox */,
+                    gpu::SyncToken /* sync_token */,
+                    bool /* is_lost */)
+
 // Wait until the token is in a specific range, inclusive.
 IPC_SYNC_MESSAGE_ROUTED2_1(GpuCommandBufferMsg_WaitForTokenInRange,
                            int32_t /* start */,