Initial checkin of accessibility extensions.

ui/accessibility/extensions/alt/hide-images.css

Index: ui/accessibility/extensions/alt/hide-images.css
diff --git a/ui/accessibility/extensions/alt/hide-images.css b/ui/accessibility/extensions/alt/hide-images.css
new file mode 100644
index 0000000000000000000000000000000000000000..a9d30e333a958551e640521a240774ab3650f43c
--- /dev/null
+++ b/ui/accessibility/extensions/alt/hide-images.css
@@ -0,0 +1,146 @@
+/* Copyright (c) 2014 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. */
+
+body[show-alt] img {
+    /* add some fake content to hang the ::before element off */
+    content: "" !important;
+    background-image: url('data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7')
+
+    /* display non-floated and remove any background color */
+    float: none !important;
+    background-color: inherit !important;
+
+    /* set height to contain the text content */
+    height: 100% !important;
+}
+
+body[show-alt] img:not([alt]):not([aria-hidden=true]):not([role=presentation]):before {
+    content: url('chrome-extension://__MSG_@@extension_id__/images/speech-missing-alt-16.png') " " attr(_repaired) !important;
+    box-shadow: inset 0 -4px 0 rgba(230, 124, 115, 1) !important;
+}
+
+body[show-alt] img:not([aria-hidden=true]):not([role=presentation]):not([alt='']):before {
+    content: url('chrome-extension://__MSG_@@extension_id__/images/speech-16.png') " " attr(alt) !important;
+    box-shadow: inset 0 -4px 0 rgba(139, 195, 74, 1) !important;
+    display: table;
+    clear: both;
+}
+
+@-webkit-keyframes slideDown {
+    from {
+      -webkit-transform: translateY(-150%);
+    }
+    to {
+      -webkit-transform: translateY(0px);
+    }
+}
+
+@-webkit-keyframes slideUp {
+    from {
+      -webkit-transform: translateY(0%);
+    }
+    to {
+      -webkit-transform: translateY(-150%);
+    }
+}
+
+body[show-alt] .show-alt-infobar {
+    -webkit-animation-name: slideDown;
+    -webkit-animation-duration: 0.5s;
+    -webkit-animation-delay: 0.5s;
+    -webkit-animation-iteration-count: 1;
+    -webkit-animation-timing-function: ease;
+    -webkit-animation-direction: forwards;
+    -webkit-transform: translateY(0%);
+}
+
+body:not([show-alt]) .show-alt-infobar {
+    -webkit-animation-name: slideUp;
+    -webkit-animation-duration: 0.5s;
+    -webkit-animation-delay: 0.5s;
+    -webkit-animation-iteration-count: 1;
+    -webkit-animation-timing-function: ease;
+    -webkit-animation-direction: forwards;
+    -webkit-transform: translateY(-150%);
+}
+
+.show-alt-infobar {
+    top: 0;
+    left: 0;
+    right: 0;
+    z-index: 100000001;  /* :( */
+    position: fixed !important;
+    background: #fde073 !important;
+    text-align: center !important;
+    line-height: 2.0;
+    overflow: hidden;
+    box-shadow: 0 0 5px black;
+    box-shadow:         0 0 5px black;
+    font-family: Arial, sans-serif !important;
+    font-size: 12pt !important;
+    -webkit-animation-fill-mode: backwards;
+}
+
+.show-alt-infobar .content {
+    display: inline-block !important;
+}
+
+.show-alt-infobar span {
+    margin: 5px;
+}
+
+.show-alt-infobar button.link-button {
+    -webkit-appearance: none !important;
+    font: inherit !important;
+    background: inherit !important;
+    border: none !important;
+    color: #1155CC !important;
+    cursor: pointer !important;
+    display: inline !important;
+    margin: 0 !important;
+    padding: 0 !important;
+    text-decoration: none !important;
+    box-shadow: none !important;
+    text-transform: none !important;
+    padding: none !important;
+}
+
+.show-alt-infobar button.link-button:hover,
+.show-alt-infobar button.link-button:focus {
+    color: #1155CC;
+    text-decoration: underline;
+    outline: none;
+}
+
+.show-alt-infobar .controls {
+    float: right !important;
+    display: inline-block !important;
+    padding-right: 5px !important;
+}
+
+.show-alt-infobar .close-button-gray:hover,
+.show-alt-infobar .close-button-gray:focus {
+    background-position: -143px -96px !important;
+    outline: none;
+}
+
+.show-alt-infobar .close-button-gray {
+    -webkit-appearance: none !important;
+    font: inherit !important;
+    background: inherit !important;
+    border: none !important;
+    cursor: pointer !important;
+    margin: 0 !important;
+    padding: 0 !important;
+    text-decoration: none !important;
+    box-shadow: none !important;
+    text-transform: none !important;
+    padding: none !important;
+    width: 13px !important;
+    height: 13px !important;
+    background-position: -175px -96px !important;
+    background-image: url('chrome-extension://__MSG_@@extension_id__/images/statusbarButtonGlyphs.png') !important;
+    background-size: 320px 144px !important;
+    display: inline-block !important;
+}