StreamTextureImages can now override a Texture's service id

gpu/command_buffer/service/texture_manager.cc

Index: gpu/command_buffer/service/texture_manager.cc
diff --git a/gpu/command_buffer/service/texture_manager.cc b/gpu/command_buffer/service/texture_manager.cc
index ba79b2a3890fe5bdce0c3f75fc42ecdc21000f8e..60192add4dbd9e630cdcc737e5577ee6921b65fc 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -1491,6 +1491,9 @@ void Texture::SetLevelImageInternal(GLenum target,
   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();