StreamTextureImages can now override a Texture's service id

gpu/command_buffer/service/texture_manager.cc

 // 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.
 
 #include "gpu/command_buffer/service/texture_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1473 matching lines @@
   DCHECK_LT(static_cast<size_t>(level),
             face_infos_[face_index].level_infos.size());
   Texture::LevelInfo& info =
       face_infos_[face_index].level_infos[level];
   DCHECK_EQ(info.target, target);
   DCHECK_EQ(info.level, level);
   info.image = image;
   info.stream_texture_image = stream_texture_image;
   info.image_state = state;
 
+  // Reset the unowned service id because if the previously bound image owned
+  // it, it would have become invalid when that image was destructed.
+  SetUnownedServiceId(0);

[piman, 2016/05/26 22:09:16]

I think I understand the semantics this is trying to achieve, but I wonder if we
could make it a bit more explicit, by explicitly tying the unowned service id
with the image, maybe by adding the unowned service id to
SetLevelStreamTextureImage

The idea is that this state becomes explicitly linked with the image - if you
call SetLevelImage, it becomes implicitly 0, if you call
SetLevelStreamTextureImage, it becomes whatever you pass it.

As far as I can tell, the only (external) caller of SetUnownedServiceId is
AndroidDeferredRenderingBackingStrategy::SetImageForPicture, which both set the
service id and the image.

Actually I think the current code would break without this, because that calls
SetUnownedServiceId first, then SetLevelStreamTextureImage which would reset it.
Thoughts?

   UpdateCanRenderCondition();
   UpdateHasImages();
   UpdateEmulatingRGB();
 }
 
 void Texture::SetLevelImage(GLenum target,
                             GLint level,
                             gl::GLImage* image,
                             ImageState state) {
   SetLevelImageInternal(target, level, image, nullptr, state);
@@ skipping 1805 matching lines @@
 uint32_t TextureManager::GetServiceIdGeneration() const {
   return current_service_id_generation_;
 }
 
 void TextureManager::IncrementServiceIdGeneration() {
   current_service_id_generation_++;
 }
 
 }  // namespace gles2
 }  // namespace gpu