AVDACodecImages keep their backing SurfaceTexture alive

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 61f2acc5d188873b7d6731f18e5e8e2c801f7c1f..040e15f31fd80974e9e5be9ff1e6dc5cb1addd9a 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -1487,10 +1487,17 @@ void Texture::SetLevelImageInternal(GLenum target,
       face_infos_[face_index].level_infos[level];
   DCHECK_EQ(info.target, target);
   DCHECK_EQ(info.level, level);
+  bool image_previously_bound = !!info.image;
   info.image = image;
   info.stream_texture_image = stream_texture_image;
   info.image_state = state;
 
+
+  // Clear the unowned service id because the previous image might own it, in
+  // which case it's no longer valid.
+  if (image_previously_bound && level == 0)

[liberato (no reviews please), 2016/05/26 16:59:19]

i don't think that one needs to check if an image was previously bound, or even
(probably) the level.

AVDA can set them in the right order.

also, please add documentation to texture_manager.h::SetUnownedServiceId that
it's cleared on any SetLevelImage.  else it'll confuse somebody (probably us :)
) some day.

the texture_manager changes can probably be a separate CL.  it looks like AVDA
does the SetLevel / SetUnowned calls in the right order already.  i think that
they stand on their own as a security improvement.

+    SetUnownedServiceId(0);
+
   UpdateCanRenderCondition();
   UpdateHasImages();
   UpdateEmulatingRGB();