Moved creation of GPU transfer buffers into the browser process....

chrome/common/gpu_messages_internal.h

 // Copyright (c) 2010 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 <vector>
 #include <string>
 
 #include "base/shared_memory.h"
 #include "chrome/common/gpu_info.h"
 #include "chrome/common/gpu_video_common.h"
@@ skipping 161 matching lines @@
 #elif defined(OS_WIN)
 IPC_MESSAGE_CONTROL2(GpuHostMsg_ScheduleComposite,
                      int32, /* renderer_id */
                      int32 /* render_view_id */)
 #endif
 
 //------------------------------------------------------------------------------
 // GPU Channel Messages
 // These are messages from a renderer process to the GPU process.
 
+// Initialize a channel between a renderer process and a GPU process. The
+// renderer passes a process handle to the GPU process, which gives it the

[Ken Russell (switch to Gerrit), 2011/02/24 19:48:47]

I found this really confusing to understand. I think a simple change to "The
renderer passes its process handle..." would help. Also, perhaps "gives the GPU
process the ability to map handles from the renderer process".

+// ability to map renderer handles into the GPU process. This must be the
+// first message sent on a newly connected channel.
+IPC_MESSAGE_CONTROL1(GpuChannelMsg_Initialize,
+                     base::ProcessHandle /* gpu_renderer_process */)

[Ken Russell (switch to Gerrit), 2011/02/24 19:48:47]

I found the naming convention of "gpu_renderer_process" throughout this CL
confusing, at least until finding another example ("browser_gpu_process"). Could
a different convention be used? How about "renderer_process_for_gpu"?

+
 // Tells the GPU process to create a new command buffer that renders to an
 // offscreen frame buffer. If parent_route_id is not zero, the texture backing
 // the frame buffer is mapped into the corresponding parent command buffer's
 // namespace, with the name of parent_texture_id. This ID is in the parent's
 // namespace.
 IPC_SYNC_MESSAGE_CONTROL4_1(GpuChannelMsg_CreateOffscreenCommandBuffer,
                             int32, /* parent_route_id */
                             gfx::Size, /* size */
                             GPUCreateCommandBufferConfig, /* init_params */
                             uint32, /* parent_texture_id */
@@ skipping 58 matching lines @@
 
 // Indicates that a SwapBuffers call has been issued.
 IPC_MESSAGE_ROUTED0(GpuCommandBufferMsg_SwapBuffers)
 
 // Create a shared memory transfer buffer. Returns an id that can be used to
 // identify the transfer buffer from a comment.
 IPC_SYNC_MESSAGE_ROUTED1_1(GpuCommandBufferMsg_CreateTransferBuffer,
                            int32 /* size */,
                            int32 /* id */)
 
+// Register an existing shared memory transfer buffer. Returns an id that can be
+// used to identify the transfer buffer from a command buffer.
+IPC_SYNC_MESSAGE_ROUTED2_1(GpuCommandBufferMsg_RegisterTransferBuffer,
+                           base::SharedMemoryHandle /* transfer_buffer */,
+                           size_t /* size */,
+                           int32 /* id */)
+
 // Destroy a previously created transfer buffer.
 IPC_SYNC_MESSAGE_ROUTED1_0(GpuCommandBufferMsg_DestroyTransferBuffer,
                            int32 /* id */)
 
 // Get the shared memory handle for a transfer buffer mapped to the callers
 // process.
 IPC_SYNC_MESSAGE_ROUTED1_2(GpuCommandBufferMsg_GetTransferBuffer,
                            int32 /* id */,
                            base::SharedMemoryHandle /* transfer_buffer */,
                            uint32 /* size */)
@@ skipping 93 matching lines @@
 // Release all video frames allocated for a hardware video decoder.
 IPC_MESSAGE_ROUTED0(GpuVideoDecoderHostMsg_ReleaseAllVideoFrames)
 
 // GpuVideoDecoder report output format change.
 IPC_MESSAGE_ROUTED1(GpuVideoDecoderHostMsg_MediaFormatChange,
                     GpuVideoDecoderFormatChangeParam)
 
 // GpuVideoDecoder report error.
 IPC_MESSAGE_ROUTED1(GpuVideoDecoderHostMsg_ErrorNotification,
                     GpuVideoDecoderErrorInfoParam)