Command to mark surface inactive, so gpu process can release resources.

content/common/gpu/image_transport_surface.h

 // Copyright (c) 2011 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.
 
 #ifndef CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_
 #define CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_
 #pragma once
 
 #if defined(ENABLE_GPU)
 
@@ skipping 34 matching lines @@
 // The ImageTransportSurfaceHelper provides some glue to the outside world:
 // making sure outside events reach the ImageTransportSurface and
 // allowing the ImageTransportSurface to send events to the outside world.
 
 class ImageTransportSurface {
  public:
   virtual void OnNewSurfaceACK(
       uint64 surface_id, TransportDIB::Handle surface_handle) = 0;
   virtual void OnBuffersSwappedACK() = 0;
   virtual void OnResize(gfx::Size size) = 0;
+  virtual void OnSurfaceVisible(bool visible) = 0;
 
   // Creates the appropriate surface depending on the GL implementation.
   static scoped_refptr<gfx::GLSurface>
       CreateSurface(GpuChannelManager* manager,
                     int32 render_view_id,
                     int32 renderer_id,
                     int32 command_buffer_id,
                     gfx::PluginWindowHandle handle);
 };
 
@@ skipping 33 matching lines @@
   gpu::GpuScheduler* Scheduler();
   gpu::gles2::GLES2Decoder* Decoder();
 
   // IPC::Message handlers.
   void OnNewSurfaceACK(uint64 surface_id, TransportDIB::Handle surface_handle);
   void OnBuffersSwappedACK();
 
   // Backbuffer resize callback.
   void Resize(gfx::Size size);
 
+  // Backbuffer visibility change callback.
+  void SurfaceVisible(bool visible);

[apatrick_chromium, 2011/10/07 22:45:49]

I'm still not clear why you want to add a new GL command? It seems you could
sidestep a lot of plumbing via the decoder by just sending an async IPC to this
object and having this function handle it? Is the sender not able to determine
the routing routing ID? Preceding it with an async flush will ensure that it is
not reordered relative to prior and subsequent GL commands.

[mmocny, 2011/10/11 13:58:43]

You are correct.
First I thought it would not be possible with IPC, and then that it might
slightly less efficient (glflush+IPC+(possibly)command stream flush).
Now I am wondering if it means more WebKit plumbing, and I am investigating.
I will update this CL with either a new implementation, or a reason why not.

On 2011/10/07 22:45:49, apatrick_chromium wrote:

+
   // Weak pointers that point to objects that outlive this helper.
   ImageTransportSurface* surface_;
   GpuChannelManager* manager_;
 
   int32 render_view_id_;
   int32 renderer_id_;
   int32 command_buffer_id_;
   int32 route_id_;
   gfx::PluginWindowHandle handle_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageTransportHelper);
 };
 
 #endif  // defined(ENABLE_GPU)
 
 #endif  // CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_