NOT for review (for discussion): Query IOSurfaceIsInUse in the browser process

cc/output/gl_renderer.h

 // Copyright 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.
 
 #ifndef CC_OUTPUT_GL_RENDERER_H_
 #define CC_OUTPUT_GL_RENDERER_H_
 
 #include <deque>
 #include <vector>
 
@@ skipping 246 matching lines @@
   // from |overlay_resource_pool_|.
   // The resulting Resource may be larger than the original quad. The new size
   // and position is placed in |new_bounds|.
   void CopyRenderPassDrawQuadToOverlayResource(
       const CALayerOverlay* ca_layer_overlay,
       Resource** resource,
       DrawingFrame* frame,
       gfx::RectF* new_bounds);
 
   // Schedules the |ca_layer_overlay|, which is guaranteed to have a non-null
-  // |rpdq| parameter.
-  void ScheduleRenderPassDrawQuad(const CALayerOverlay* ca_layer_overlay,
-                                  DrawingFrame* external_frame);
+  // |rpdq| parameter. Returns the resource lock for the layer contents.
+  std::unique_ptr<ResourceProvider::ScopedReadLockGL>
+  ScheduleRenderPassDrawQuad(const CALayerOverlay* ca_layer_overlay,
+                             DrawingFrame* external_frame);
 
   using OverlayResourceLock =
       std::unique_ptr<ResourceProvider::ScopedReadLockGL>;
   using OverlayResourceLockList = std::vector<OverlayResourceLock>;
 
+  // A resource lock for a resource that was used by ScheduleCALayer. The
+  // resource can only be unlocked once its GpuMemoryBuffer is no longer in
+  // use.
+  struct CALayerResourceLock {
+    CALayerResourceLock();
+    ~CALayerResourceLock();
+    CALayerResourceLock(CALayerResourceLock&& ca_layer_resource);
+
+    uint32_t outstanding_ack_count = 0;
+    std::unique_ptr<ResourceProvider::ScopedReadLockGL> lock;
+    std::unique_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer;
+    bool in_use_valid = false;
+  };
+  std::map<unsigned, CALayerResourceLock> ca_layer_resources_;
+
   // Resources that have been sent to the GPU process, but not yet swapped.
   OverlayResourceLockList pending_overlay_resources_;
 
   // Resources that should be shortly swapped by the GPU process.
   std::deque<OverlayResourceLockList> swapping_overlay_resources_;
 
-  // Resources that the GPU process has finished swapping. The key is the
-  // texture id of the resource.
-  std::map<unsigned, OverlayResourceLock> swapped_and_acked_overlay_resources_;
-
   unsigned offscreen_framebuffer_id_;
 
   std::unique_ptr<StaticGeometryBinding> shared_geometry_;
   std::unique_ptr<DynamicGeometryBinding> clipped_geometry_;
   gfx::QuadF shared_geometry_quad_;
 
   // This block of bindings defines all of the programs used by the compositor
   // itself.  Add any new programs here to GLRendererShaderTest.
 
   // Tiled layer shaders.
@@ skipping 246 matching lines @@
   bool force_drawing_frame_framebuffer_unflipped_ = false;
 
   BoundGeometry bound_geometry_;
   ColorLUTCache color_lut_cache_;
   DISALLOW_COPY_AND_ASSIGN(GLRenderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_GL_RENDERER_H_