Merge some byte swap/premultiply functions in their own crate

components/canvas/Cargo.toml

@@ -24,6 +24,7 @@ ipc-channel = "0.11"
 log = "0.4"
 num-traits = "0.2"
 offscreen_gl_context = {version = "0.21", features = ["serde", "osmesa"]}
+pixels = {path = "../pixels"}
 serde_bytes = "0.10"
 servo_config = {path = "../config"}
 webrender = {git = "https://github.com/servo/webrender"}

components/canvas/canvas_paint_thread.rs

@@ -7,6 +7,7 @@ use canvas_data::*;
 use canvas_traits::canvas::*;
 use euclid::Size2D;
 use ipc_channel::ipc::{self, IpcSender};
+use pixels;
 use std::borrow::ToOwned;
 use std::collections::HashMap;
 use std::thread;
@@ -141,7 +142,7 @@ impl<'a> CanvasPaintThread <'a> {
                 let data = match imagedata {
                     None => vec![0; image_size.width as usize * image_size.height as usize * 4],
                     Some(mut data) => {
-                        byte_swap(&mut data);
+                        pixels::byte_swap_colors_inplace(&mut data);
                         data.into()
                     },
                 };

components/canvas/lib.rs

@@ -15,6 +15,7 @@ extern crate ipc_channel;
 #[macro_use] extern crate log;
 extern crate num_traits;
 extern crate offscreen_gl_context;
+extern crate pixels;
 extern crate serde_bytes;
 extern crate servo_config;
 extern crate webrender;

components/canvas/webgl_thread.rs

@@ -2,13 +2,13 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use canvas_traits::canvas::byte_swap;
 use canvas_traits::webgl::*;
 use euclid::Size2D;
 use fnv::FnvHashMap;
 use gleam::gl;
 use ipc_channel::ipc::IpcBytesSender;
 use offscreen_gl_context::{GLContext, GLContextAttributes, GLLimits, NativeGLContextMethods};
+use pixels;
 use std::thread;
 use super::gl_context::{GLContextFactory, GLContextWrapper};
 use webrender;
@@ -562,7 +562,7 @@ impl<VR: WebVRRenderHandler + 'static> WebGLThread<VR> {
             let src_slice = &orig_pixels[src_start .. src_start + stride];
             (&mut pixels[dst_start .. dst_start + stride]).clone_from_slice(&src_slice[..stride]);
         }
-        byte_swap(&mut pixels);
+        pixels::byte_swap_colors_inplace(&mut pixels);
         pixels
     }