Pepper takes ownership of a mailbox before passing it to the texture layer.

cc/layers/texture_layer.cc

Index: cc/layers/texture_layer.cc
diff --git a/cc/layers/texture_layer.cc b/cc/layers/texture_layer.cc
index b5b31732ac88dd356dd6974d448dd4135b6602a9..eab540ecb9743cb087a6e48ae2586e2c6b96a94f 100644
--- a/cc/layers/texture_layer.cc
+++ b/cc/layers/texture_layer.cc
@@ -154,26 +154,6 @@ void TextureLayer::SetTextureMailbox(
                             requires_commit, allow_mailbox_reuse);
 }
 
-static void IgnoreReleaseCallback(const gpu::SyncToken& sync_token, bool lost) {

[ccameron, 2016/04/22 18:25:54]

:D

-}
-
-void TextureLayer::SetTextureMailboxWithoutReleaseCallback(
-    const TextureMailbox& mailbox) {
-  // We allow reuse of the mailbox if there is a new sync point signalling new
-  // content, and the release callback goes nowhere since we'll be calling it
-  // multiple times for the same mailbox.
-  DCHECK(!mailbox.IsValid() || !holder_ref_ ||
-         !mailbox.Equals(holder_ref_->holder()->mailbox()) ||
-         mailbox.sync_token() != holder_ref_->holder()->mailbox().sync_token());
-  std::unique_ptr<SingleReleaseCallback> release;
-  bool requires_commit = true;
-  bool allow_mailbox_reuse = true;
-  if (mailbox.IsValid())
-    release = SingleReleaseCallback::Create(base::Bind(&IgnoreReleaseCallback));
-  SetTextureMailboxInternal(mailbox, std::move(release), requires_commit,
-                            allow_mailbox_reuse);
-}
-
 void TextureLayer::SetNeedsDisplayRect(const gfx::Rect& dirty_rect) {
   Layer::SetNeedsDisplayRect(dirty_rect);
 }