Fix some build warnings

- Mark some instances of unused fields and variables as as allowed,
  when they are used for memory management.
- Remove the use of some deprecated function.s

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/components/script/dom/htmlcanvaselement.rs b/components/script/dom/htmlcanvaselement.rs
index 3094b126eb5..33f0c6c6a34 100644
--- a/components/script/dom/htmlcanvaselement.rs
+++ b/components/script/dom/htmlcanvaselement.rs
@@ -38,7 +38,7 @@ use dom_struct::dom_struct;
 use euclid::default::{Rect, Size2D};
 use html5ever::{LocalName, Prefix};
 use image::codecs::png::PngEncoder;
-use image::ColorType;
+use image::{ColorType, ImageEncoder};
 use ipc_channel::ipc::{self as ipcchan, IpcSharedMemory};
 use js::error::throw_type_error;
 use js::rust::HandleValue;
@@ -427,7 +427,7 @@ impl HTMLCanvasElementMethods for HTMLCanvasElement {
         // FIXME(nox): https://github.com/image-rs/image-png/issues/86
         // FIXME(nox): https://github.com/image-rs/image-png/issues/87
         PngEncoder::new(&mut png)
-            .encode(&file, self.Width(), self.Height(), ColorType::Rgba8)
+            .write_image(&file, self.Width(), self.Height(), ColorType::Rgba8)
             .unwrap();
         let mut url = "data:image/png;base64,".to_owned();
         // FIXME(nox): Should this use base64::URL_SAFE?