Drop frontbuffers with ui-use-gpu-process, synchronized with browser, decoupled from backbuffer dro…

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 <vector>
 #include <string>
 
@@ skipping 66 matching lines @@
 
 IPC_STRUCT_BEGIN(GpuHostMsg_AcceleratedSurfaceRelease_Params)
   IPC_STRUCT_MEMBER(int32, surface_id)
   IPC_STRUCT_MEMBER(uint64, identifier)
   IPC_STRUCT_MEMBER(int32, route_id)
 #if defined(OS_MACOSX)
   IPC_STRUCT_MEMBER(gfx::PluginWindowHandle, window)
 #endif
 IPC_STRUCT_END()
 
+IPC_STRUCT_BEGIN(GpuHostMsg_AcceleratedSurfaceSuggestDiscard_Params)
+  IPC_STRUCT_MEMBER(int32, surface_id)
+  IPC_STRUCT_MEMBER(uint64, identifier)
+  IPC_STRUCT_MEMBER(int32, route_id)
+IPC_STRUCT_END()
+
 IPC_STRUCT_BEGIN(GPUCommandBufferConsoleMessage)
   IPC_STRUCT_MEMBER(int32, id)
   IPC_STRUCT_MEMBER(std::string, message)
 IPC_STRUCT_END()
 
 IPC_STRUCT_TRAITS_BEGIN(content::DxDiagNode)
   IPC_STRUCT_TRAITS_MEMBER(values)
   IPC_STRUCT_TRAITS_MEMBER(children)
 IPC_STRUCT_TRAITS_END()
 
@@ skipping 88 matching lines @@
 
 // Tells the GPU process that the browser process has finished resizing the
 // view.
 IPC_MESSAGE_ROUTED0(AcceleratedSurfaceMsg_ResizeViewACK)
 
 // Tells the GPU process that it's safe to start rendering to the surface.
 IPC_MESSAGE_ROUTED2(AcceleratedSurfaceMsg_NewACK,
                     uint64 /* surface_handle */,
                     TransportDIB::Handle /* shared memory buffer */)
 
+// Tells the GPU process that it's safe to release the surface.
+IPC_MESSAGE_ROUTED1(AcceleratedSurfaceMsg_DiscardSurface,
+                    uint64 /* surface_id */)
+
 // Tells the GPU process that the browser process handled the swap
 // buffers request.
 IPC_MESSAGE_ROUTED0(AcceleratedSurfaceMsg_BuffersSwappedACK)
 
 // Tells the GPU process that the browser process handled the
 // PostSubBuffer command.
 IPC_MESSAGE_ROUTED0(AcceleratedSurfaceMsg_PostSubBufferACK)
 
 // Tells the GPU process to remove all contexts.
 IPC_MESSAGE_CONTROL0(GpuMsg_Clean)
@@ skipping 75 matching lines @@
 // the given surface. The browser must send an ACK once this operation
 // is complete.
 IPC_MESSAGE_CONTROL1(GpuHostMsg_AcceleratedSurfaceRelease,
                      GpuHostMsg_AcceleratedSurfaceRelease_Params)
 
 // Tells the browser to release resources for the given surface until the next
 // time swap buffers or post sub buffer is sent.
 IPC_MESSAGE_CONTROL1(GpuHostMsg_AcceleratedSurfaceSuspend,
                      int32 /* surface_id */)
 
+// Tells the browser to release resources for the given surface until the next
+// time swap buffers or post sub buffer is sent.
+IPC_MESSAGE_CONTROL1(GpuHostMsg_AcceleratedSurfaceSuggestDiscard,
+                     GpuHostMsg_AcceleratedSurfaceSuggestDiscard_Params)
+
 //------------------------------------------------------------------------------
 // GPU Channel Messages
 // These are messages from a renderer process to the GPU process.
 
 // Tells the GPU process to create a new command buffer that renders to an
 // offscreen frame buffer.
 IPC_SYNC_MESSAGE_CONTROL2_1(GpuChannelMsg_CreateOffscreenCommandBuffer,
                             gfx::Size, /* size */
                             GPUCreateCommandBufferConfig, /* init_params */
                             int32 /* route_id */)
@@ skipping 208 matching lines @@
 
 // Confirm decoder has been flushed.
 IPC_MESSAGE_ROUTED0(AcceleratedVideoDecoderHostMsg_FlushDone)
 
 // Confirm decoder has been reset.
 IPC_MESSAGE_ROUTED0(AcceleratedVideoDecoderHostMsg_ResetDone)
 
 // Video decoder has encountered an error.
 IPC_MESSAGE_ROUTED1(AcceleratedVideoDecoderHostMsg_ErrorNotification,
                     uint32) /* Error ID */