Add color enhancer as a chromium accessibility extensions.

BUG=

Review URL: https://codereview.chromium.org/984833004

Cr-Commit-Position: refs/heads/master@{#320514}

ui/accessibility/extensions/accessibility_extensions.gyp

@@ -13,6 +13,7 @@
       'dependencies': [
         'alt',
         'caretbrowsing',
+        'colorenhancer',
         'highcontrast',
         'longdesc',
       ]
@@ -100,6 +101,41 @@
         },
       ],
     },
+    {
+      'target_name': 'colorenhancer',
+      'type': 'none',
+      'copies': [
+        {
+          'destination': '<(dest_dir)/colorenhancer',
+          'files': [
+            'colorenhancer/res/cvd-128.png',
+            'colorenhancer/res/cvd-16.png',
+            'colorenhancer/res/cvd-19.png',
+            'colorenhancer/res/cvd-38.png',
+            'colorenhancer/res/cvd-48.png',
+            'colorenhancer/res/cvd.css',
+            'colorenhancer/manifest.json',
+            'colorenhancer/src/background.js',
+            'colorenhancer/src/common.js',
+            'colorenhancer/src/cvd.js',
+            'colorenhancer/src/popup.html',
+            'colorenhancer/src/popup.js',
+          ]
+        }
+      ],
+      'actions': [
+        {
+          'action_name': 'colorenhancer_strings',
+          'variables': {
+            'grit_grd_file': 'strings/accessibility_extensions_strings.grd',
+            'grit_out_dir': '<(dest_dir)/colorenhancer',
+            # We don't generate any RC files, so no resource_ds file is needed.
+            'grit_resource_ids': '',
+          },
+          'includes': [ '../../../build/grit_action.gypi' ],
+        },
+      ],
+    },
     {
       'target_name': 'highcontrast',
       'type': 'none',

ui/accessibility/extensions/colorenhancer/manifest.json

@@ -0,0 +1,45 @@
+{
+  "name": "__MSG_COLOR_ENHANCER_APPNAME__",
+  "version": "1.1.2",
+  "description": "__MSG_COLOR_ENHANCER_APPDESC__",
+  "manifest_version": 2,
+  "icons": {
+    "16": "res/cvd-16.png",
+    "48": "res/cvd-48.png",
+    "128": "res/cvd-128.png"
+  },
+  "permissions": [
+    "<all_urls>",
+    "tabs"
+  ],
+  "background": {
+    "scripts": [
+      "src/common.js",
+      "src/storage.js",
+      "src/background.js"
+    ]
+  },
+  "browser_action": {
+    "default_icon": {
+      "19": "res/cvd-19.png",
+      "38": "res/cvd-38.png"
+    },
+    "default_title": "__MSG_COLOR_ENHANCER_APPNAME__",
+    "default_popup": "src/popup.html"
+  },
+  "content_scripts": [
+    {
+      "run_at": "document_start",
+      "matches": [
+        "<all_urls>"
+      ],
+      "css": [
+        "res/cvd.css"
+      ],
+      "js": [
+        "src/common.js",
+        "src/cvd.js"
+      ]
+    }
+  ]
+}

ui/accessibility/extensions/colorenhancer/res/cvd.css

@@ -0,0 +1,11 @@
+/* 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. */
+
+html.filter0 {
+  -webkit-filter: url('#cvd_extension_0');
+}
+
+html.filter1 {
+  -webkit-filter: url('#cvd_extension_1');
+}

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

@@ -0,0 +1,96 @@
+// 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 (isDisallowedUrl(url)) {
+          continue;
+        }
+        chrome.tabs.insertCSS(
+            tabs[j].id,
+            {file: 'res/cvd.css'});
+        chrome.tabs.executeScript(
+            tabs[j].id,
+            {file: 'src/common.js'});
+        chrome.tabs.executeScript(
+            tabs[j].id,
+            {file: 'src/cvd.js'});
+      }
+    }
+  });
+}
+
+/**
+ * Updates all existing tabs with config values.
+ */
+function updateTabs() {
+  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;
+        }
+        debugPrint('sending  to ' + siteFromUrl(url) + ' ' +
+            getSiteDelta(siteFromUrl(url)) + ',' +
+            getSiteSeverity(siteFromUrl(url)));
+        var msg = {
+          'delta': getSiteDelta(siteFromUrl(url)),
+          'severity': getSiteSeverity(siteFromUrl(url)),
+          'type': getDefaultType(),
+          'simulate': getDefaultSimulate()
+        };
+        chrome.tabs.sendRequest(tabs[j].id, msg);
+      }
+    }
+  });
+}
+
+/**
+ * Initial extension loading.
+ */
+(function initialize() {
+  injectContentScripts();
+  updateTabs();
+
+  chrome.extension.onRequest.addListener(
+      function(request, sender, sendResponse) {
+        if (request['init']) {
+          var delta = getDefaultDelta();
+          if (sender.tab) {
+            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 = {
+            'delta': delta,
+            'severity': severity,
+            'type': getDefaultType(),
+            'simulate': getDefaultSimulate()
+          };
+          sendResponse(msg);
+        }
+      });
+
+  document.addEventListener('storage', function(evt) {
+    updateTabs();
+  }, false);
+})();

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

@@ -0,0 +1,54 @@
+// 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.
+
+// TODO(wnwen): Move most of these functions to their own page rather than
+//     common, which should be shared with content script.
+
+/**
+ * TODO(wnwen): Remove this and use actual web API.
+ */
+function $(id) {
+  return document.getElementById(id);
+}
+
+
+/**
+ * TODO(wnwen): Remove this, it's terrible.
+ */
+function siteFromUrl(url) {
+  var a = document.createElement('a');
+  a.href = url;
+  return a.hostname;
+}
+
+
+/**
+ * The filter should not apply to these URLs.
+ *
+ * @param {string} url The URL to check.
+ */
+function isDisallowedUrl(url) {
+  return url.indexOf('chrome') == 0 || url.indexOf('about') == 0;
+}
+
+
+/**
+ * Whether extension is loaded unpacked or from Chrome Webstore.
+ */
+function isDevMode = function() {
+  return !('update_url' in chrome.runtime.getManifest());
+}
+
+
+/**
+ * Easily turn on/off console logs.
+ *
+ * @param {*} message The message to potentially pass to {@code console.log}.
+ */
+var debugPrint;
+if (isDevMode()) {
+  debugPrint = console.log;
+} else {
+  debugPrint = function() {};
+}