Clean up GPU back-pressure with remote CALayers

content/common/gpu/gpu_messages.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.
 
 // Multiply-included message file, hence no include guard here, but see below
 // for a much smaller-than-usual include guard section.
 
 #include <string>
 #include <vector>
 
@@ skipping 63 matching lines @@
 
 IPC_STRUCT_BEGIN(GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params)
   IPC_STRUCT_MEMBER(int32, surface_id)
   IPC_STRUCT_MEMBER(uint64, surface_handle)
   IPC_STRUCT_MEMBER(int32, route_id)
   IPC_STRUCT_MEMBER(gfx::Size, size)
   IPC_STRUCT_MEMBER(float, scale_factor)
   IPC_STRUCT_MEMBER(std::vector<ui::LatencyInfo>, latency_info)
 IPC_STRUCT_END()
 
+#if defined(OS_MACOSX)
 IPC_STRUCT_BEGIN(AcceleratedSurfaceMsg_BufferPresented_Params)
+  // If the browser needs framerate throttling based on GPU back-pressure to be
+  // disabled (e.g, because the NSView isn't visible but tab capture is active),
+  // then this is set to true.
+  IPC_STRUCT_MEMBER(bool, disable_throttling)
+  // If the browser is drawing to the screen, this is the CGL renderer ID of
+  // the GL context that the brower is using.
   IPC_STRUCT_MEMBER(int32, renderer_id)
 IPC_STRUCT_END()
+#endif
 
 IPC_STRUCT_BEGIN(GPUCommandBufferConsoleMessage)
   IPC_STRUCT_MEMBER(int32, id)
   IPC_STRUCT_MEMBER(std::string, message)
 IPC_STRUCT_END()
 
 #if defined(OS_ANDROID)
 IPC_STRUCT_BEGIN(GpuStreamTextureMsg_MatrixChanged_Params)
   IPC_STRUCT_MEMBER(float, m00)
   IPC_STRUCT_MEMBER(float, m01)
@@ skipping 168 matching lines @@
                      gfx::GpuMemoryBufferHandle, /* handle */
                      int32 /* sync_point */)
 
 // Tells the GPU process to create a context for collecting graphics card
 // information.
 IPC_MESSAGE_CONTROL0(GpuMsg_CollectGraphicsInfo)
 
 // Tells the GPU process to report video_memory information for the task manager
 IPC_MESSAGE_CONTROL0(GpuMsg_GetVideoMemoryUsageStats)
 
+#if defined(OS_MACOSX)
 // Tells the GPU process that the browser process has handled the swap
-// buffers or post sub-buffer request. A non-zero sync point means
-// that we should wait for the sync point. The surface_handle identifies
-// that buffer that has finished presented, i.e. the buffer being returned.
+// buffers or post sub-buffer request.
 IPC_MESSAGE_ROUTED1(AcceleratedSurfaceMsg_BufferPresented,
                     AcceleratedSurfaceMsg_BufferPresented_Params)
+#endif
 
 // Tells the GPU process to wake up the GPU because we're about to draw.
 IPC_MESSAGE_ROUTED0(AcceleratedSurfaceMsg_WakeUpGpu)
 
 // Tells the GPU process to remove all contexts.
 IPC_MESSAGE_CONTROL0(GpuMsg_Clean)
 
 // Tells the GPU process to crash.
 IPC_MESSAGE_CONTROL0(GpuMsg_Crash)
 
@@ skipping 425 matching lines @@
                     int32 /* bitstream_buffer_id */,
                     uint32 /* payload_size */,
                     bool /* key_frame */)
 
 // Report error condition.
 IPC_MESSAGE_ROUTED1(AcceleratedVideoEncoderHostMsg_NotifyError,
                     media::VideoEncodeAccelerator::Error /* error */)
 
 // Send destroy request to the encoder.
 IPC_MESSAGE_ROUTED0(AcceleratedVideoEncoderMsg_Destroy)