Revert of [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 d58264da15eb334cc9723e3e72d95ca0b9d7f527..85800540230c2c5ca35fc271aee41c612c96f2b8 100644
--- a/gpu/ipc/common/gpu_messages.h
+++ b/gpu/ipc/common/gpu_messages.h
@@ -138,16 +138,10 @@
 IPC_SYNC_MESSAGE_ROUTED1_0(GpuCommandBufferMsg_SetGetBuffer,
                            int32_t /* shm_id */)
 
-// Takes the front buffer into a mailbox. This allows another context to draw
+// Produces the front buffer into a mailbox. This allows another context to draw
 // the output of this context.
-IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_TakeFrontBuffer,
+IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_ProduceFrontBuffer,
                     gpu::Mailbox /* mailbox */)
-
-// Returns a front buffer taken with GpuCommandBufferMsg_TakeFrontBuffer. This
-// allows it to be reused.
-IPC_MESSAGE_ROUTED2(GpuCommandBufferMsg_ReturnFrontBuffer,
-                    gpu::Mailbox /* mailbox */,
-                    bool /* is_lost */)
 
 // Wait until the token is in a specific range, inclusive.
 IPC_SYNC_MESSAGE_ROUTED2_1(GpuCommandBufferMsg_WaitForTokenInRange,
@@ -200,12 +194,6 @@
                     base::TimeTicks /* timebase */,
                     base::TimeDelta /* interval */)
 
-// The receiver will stop processing messages until the Synctoken is signaled.
-IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_WaitSyncToken,
-                    gpu::SyncToken /* sync_token */)
-
-// The receiver will asynchronously wait until the SyncToken is signaled, and
-// then return a GpuCommandBufferMsg_SignalAck message.
 IPC_MESSAGE_ROUTED2(GpuCommandBufferMsg_SignalSyncToken,
                     gpu::SyncToken /* sync_token */,
                     uint32_t /* signal_id */)