ExternalVKImageBacking: make current before delete texture passthrough

Bug: 1020626
Change-Id: I70860caa686d221c3346eaaa018f9304c04a6f5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1955864
Commit-Queue: Peng Huang <penghuang@chromium.org>
Commit-Queue: Vasiliy Telezhnikov <vasilyt@chromium.org>
Auto-Submit: Peng Huang <penghuang@chromium.org>
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#722575}

gpu/command_buffer/service/external_vk_image_backing.cc

@@ -516,7 +516,12 @@ void ExternalVkImageBacking::Destroy() {
       context_state()->MakeCurrent(nullptr, true /* need_gl */);
     texture_->RemoveLightweightRef(have_context());
   }
+
   if (texture_passthrough_) {
+    // Ensure that a context is current before releasing |texture_passthrough_|,
+    // it calls glDeleteTextures.
+    if (!gl::GLContext::GetCurrent())
+      context_state()->MakeCurrent(nullptr, true /* need_gl */);
     if (!have_context())
       texture_passthrough_->MarkContextLost();
     texture_passthrough_ = nullptr;