Add color enhancer as a chromium accessibility extensions.

ui/accessibility/extensions/colorenhancer/src/background.js

-// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+/**
+ * Adds filter script and css to all existing tabs.
+ *
+ * TODO(wnwen): Verify content scripts are not being injected multiple times.
+ */
 function injectContentScripts() {
   chrome.windows.getAll({'populate': true}, function(windows) {
     for (var i = 0; i < windows.length; i++) {
       var tabs = windows[i].tabs;
       for (var j = 0; j < tabs.length; j++) {
         var url = tabs[j].url;
-        if (url.indexOf('chrome') == 0 || url.indexOf('about') == 0) {
+        if (isDisallowedUrl(url)) {
           continue;
         }
         chrome.tabs.insertCSS(
             tabs[j].id,
-            {file: 'highcontrast.css', allFrames: true});
+            {file: 'res/cvd.css'});
         chrome.tabs.executeScript(
             tabs[j].id,
-            {file: 'highcontrast.js', allFrames: true});
+            {file: 'src/cvd.js'});
       }
     }
   });
 }
 
+/**
+ * Updates all existing tabs with config values.
+ */
 function updateTabs() {
-  var msg = {
-    'enabled': getEnabled()
-  };
   chrome.windows.getAll({'populate': true}, function(windows) {
     for (var i = 0; i < windows.length; i++) {
       var tabs = windows[i].tabs;
       for (var j = 0; j < tabs.length; j++) {
         var url = tabs[j].url;
         if (isDisallowedUrl(url)) {
           continue;
         }
+        console.log('sending  to ' + siteFromUrl(url) + ' ' +

[kevers, 2015/03/10 14:07:51]

Please wrap console log in a helper function so that it is visible as console
spam only when debugging.

[Peter Wen, 2015/03/10 19:00:55]

Done.

+                    getSiteDelta(siteFromUrl(url)) + ',' +
+                    getSiteSeverity(siteFromUrl(url)));
         var msg = {
-          'enabled': getEnabled(),
-          'scheme': getSiteScheme(siteFromUrl(url))
+          'delta': getSiteDelta(siteFromUrl(url)),
+          'severity': getSiteSeverity(siteFromUrl(url)),
+          'type': getDefaultType(),
+          'simulate': getDefaultSimulate()
         };
         chrome.tabs.sendRequest(tabs[j].id, msg);
       }
     }
   });
 }
 
-function toggleEnabled() {
-  setEnabled(!getEnabled());
-  updateTabs();
-}
-
-function toggleSite(url) {
-  var site = siteFromUrl(url);
-  var scheme = getSiteScheme(site);
-  if (scheme > 0) {
-    scheme = 0;
-  } else if (getDefaultScheme() > 0) {
-    scheme = getDefaultScheme();
-  } else {
-    scheme = DEFAULT_SCHEME;
-  }
-  setSiteScheme(site, scheme);
-  updateTabs();
-}
-
-function init() {
+/**
+ * Initial extension loading.
+ */
+(function initialize() {
   injectContentScripts();
   updateTabs();
 
   chrome.extension.onRequest.addListener(
       function(request, sender, sendResponse) {
-        if (request['toggle_global']) {
-          toggleEnabled();
-        }
-        if (request['toggle_site']) {
-          toggleSite(sender.tab ? sender.tab.url : 'www.example.com');
-        }
         if (request['init']) {
-          var scheme = getDefaultScheme();
+          var delta = getDefaultDelta();
           if (sender.tab) {
-            scheme = getSiteScheme(siteFromUrl(sender.tab.url));
+            delta = getSiteDelta(siteFromUrl(sender.tab.url));
           }
+
+          var severity = getDefaultSeverity();
+          if (sender.tab) {
+            severity = getSiteSeverity(siteFromUrl(sender.tab.url));
+          }
+
+          var type = getDefaultType();
+          var simulate = getDefaultSimulate();
+
           var msg = {
-            'enabled': getEnabled(),
-            'scheme': scheme
+            'delta': delta,
+            'severity': severity,
+            'type': getDefaultType(),
+            'simulate': getDefaultSimulate()
           };
           sendResponse(msg);
         }
       });
 
   document.addEventListener('storage', function(evt) {
     updateTabs();
   }, false);
-
-  if (navigator.appVersion.indexOf('Mac') != -1) {
-    chrome.browserAction.setTitle({'title': 'High Contrast (Cmd+Shift+F11)'});
-  }
-}
-
-init();
+})();