Rename messages forwarded from the constellation to the compositor (#30496)

The constellation forwards messages from other tasks to the compositor.
Mainly, these are passed to WebRender. This change updates the names of
these messages so it is clearer where they are coming from and where
they are going.

components/net_traits/lib.rs

@@ -823,23 +823,23 @@ pub fn http_percent_encode(bytes: &[u8]) -> String {
 }
 
 #[derive(Deserialize, Serialize)]
-pub enum WebrenderImageMsg {
+pub enum NetToCompositorMsg {
     AddImage(ImageKey, ImageDescriptor, ImageData),
     GenerateImageKey(IpcSender<ImageKey>),
 }
 
 #[derive(Clone, Deserialize, Serialize)]
-pub struct WebrenderIpcSender(IpcSender<WebrenderImageMsg>);
+pub struct WebrenderIpcSender(IpcSender<NetToCompositorMsg>);
 
 impl WebrenderIpcSender {
-    pub fn new(sender: IpcSender<WebrenderImageMsg>) -> Self {
+    pub fn new(sender: IpcSender<NetToCompositorMsg>) -> Self {
         Self(sender)
     }
 
     pub fn generate_image_key(&self) -> ImageKey {
         let (sender, receiver) = ipc::channel().unwrap();
         self.0
-            .send(WebrenderImageMsg::GenerateImageKey(sender))
+            .send(NetToCompositorMsg::GenerateImageKey(sender))
             .expect("error sending image key generation");
         receiver.recv().expect("error receiving image key result")
     }
@@ -847,7 +847,7 @@ impl WebrenderIpcSender {
     pub fn add_image(&self, key: ImageKey, descriptor: ImageDescriptor, data: ImageData) {
         if let Err(e) = self
             .0
-            .send(WebrenderImageMsg::AddImage(key, descriptor, data))
+            .send(NetToCompositorMsg::AddImage(key, descriptor, data))
         {
             warn!("Error sending image update: {}", e);
         }