Add a new command buffer function glScheduleCALayerInUseQueryCHROMIUM.

ui/gl/gl_surface.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.
 
 #ifndef UI_GL_GL_SURFACE_H_
 #define UI_GL_GL_SURFACE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 166 matching lines @@
                                const gfx::RectF& contents_rect,
                                float opacity,
                                unsigned background_color,
                                unsigned edge_aa_mask,
                                const gfx::RectF& rect,
                                bool is_clipped,
                                const gfx::RectF& clip_rect,
                                const gfx::Transform& transform,
                                int sorting_content_id,
                                unsigned filter);
+  struct CALayerInUseQuery {
+    unsigned texture;
+    GLImage* image;

[piman, 2016/06/14 00:58:56]

I think you want to take a scoped_refptr<GLImage> here, in case the client
destroys the image before the swap.

Side note, we should probably document the semantics in that case.

[erikchen, 2016/06/14 01:47:51]

ImageTransportSurfaceOverlayMac holds on to the underlying IOSurfaceRef, not the
GLImage. That being said, I prefer smart pointers to raw pointers, so I made the
change anyways.

I documented the semantics more clearly in CHROMIUM_schedule_ca_layer.txt.

"""
Clients should not destroy any textures while they are being queried, as the
swap ACK will use the original texture id to identify the queried textures.
"""
Note that there is never any confusion from the service, since |texture| is
treated as an opaque id.

I also updated the documentation in ImageTransportSurfaceOverlayMac
"""
	 109     // It's possible that the client will have destroyed the texture
before
 110     // SwapBuffersInternal is called. It's important that |texture| is only
used
 111     // as an opaque identifier, since it may no longer point to the same
 112     // texture."""

+  };
+  virtual void ScheduleCALayerInUseQuery(
+      std::vector<CALayerInUseQuery> queries);
 
   virtual bool IsSurfaceless() const;
 
   virtual bool FlipsVertically() const;
 
   // Returns true if SwapBuffers or PostSubBuffers causes a flip, such that
   // the next buffer may be 2 frames old.
   virtual bool BuffersFlipped() const;
 
   static GLSurface* GetCurrent();
@@ skipping 76 matching lines @@
 
 // Wraps GLSurface in scoped_refptr and tries to initializes it. Returns a
 // scoped_refptr containing the initialized GLSurface or nullptr if
 // initialization fails.
 GL_EXPORT scoped_refptr<GLSurface> InitializeGLSurface(
     scoped_refptr<GLSurface> surface);
 
 }  // namespace gl
 
 #endif  // UI_GL_GL_SURFACE_H_