Added TodoMVC startup benchmarks.

samples/third_party/todomvc_performance/js_todomvc/elements/td-todos.css

+/* base.css overrides */
+
+@host { 
+        * { 
+                display: block;
+                position: relative;
+        }
+}
+
+button {
+        margin: 0;
+        padding: 0;
+        border: 0;
+        background: none;
+        font-size: 100%;
+        vertical-align: baseline;
+        font-family: inherit;
+        color: inherit;
+        -webkit-appearance: none;
+        /*-moz-appearance: none;*/
+        -ms-appearance: none;
+        -o-appearance: none;
+        appearance: none;
+}
+
+input::-webkit-input-placeholder {
+        font-style: italic;
+}
+
+input::-moz-placeholder {
+        font-style: italic;
+        color: #a9a9a9;
+}
+
+input:-ms-input-placeholder, #new-todo:-ms-input-placeholder {
+        font-style: italic;
+        color: #a9a9a9;
+}
+
+#todoapp {
+        background: #fff;
+        background: rgba(255, 255, 255, 0.9);
+        /*margin: 130px 0 40px 0;*/
+        margin: 0 0 40px 0;
+        border: 1px solid #ccc;
+        position: relative;
+        border-top-left-radius: 2px;
+        border-top-right-radius: 2px;
+        box-shadow: 0 2px 6px 0 rgba(0, 0, 0, 0.2),
+                                0 25px 50px 0 rgba(0, 0, 0, 0.15);
+}
+
+#todoapp:before {
+        content: '';
+        border-left: 1px solid #f5d6d6;
+        border-right: 1px solid #f5d6d6;
+        width: 2px;
+        position: absolute;
+        top: 0;
+        left: 40px;
+        height: 100%;
+}
+
+#header {
+        padding-top: 15px;
+        border-radius: inherit;
+}
+
+#header:before {
+        content: '';
+        position: absolute;
+        top: 0;
+        right: 0;
+        left: 0;
+        height: 15px;
+        z-index: 2;
+        border-bottom: 1px solid #6c615c;
+        background: #8d7d77;
+        background: -webkit-gradient(linear, left top, left bottom, from(rgba(132, 110, 100, 0.8)),to(rgba(101, 84, 76, 0.8)));
+        background: -webkit-linear-gradient(top, rgba(132, 110, 100, 0.8), rgba(101, 84, 76, 0.8));
+        background: -moz-linear-gradient(top, rgba(132, 110, 100, 0.8), rgba(101, 84, 76, 0.8));
+        background: -o-linear-gradient(top, rgba(132, 110, 100, 0.8), rgba(101, 84, 76, 0.8));
+        background: -ms-linear-gradient(top, rgba(132, 110, 100, 0.8), rgba(101, 84, 76, 0.8));
+        background: linear-gradient(top, rgba(132, 110, 100, 0.8), rgba(101, 84, 76, 0.8));
+        filter: progid:DXImageTransform.Microsoft.gradient(GradientType=0,StartColorStr='#9d8b83', EndColorStr='#847670');
+        border-top-left-radius: 1px;
+        border-top-right-radius: 1px;
+}
+
+#new-todo,
+.edit {
+        position: relative;
+        margin: 0;
+        width: 100%;
+        font-size: 24px;
+        font-family: inherit;
+        line-height: 1.4em;
+        border: 0;
+        outline: none;
+        color: inherit;
+        padding: 6px;
+        border: 1px solid #999;
+        box-shadow: inset 0 -1px 5px 0 rgba(0, 0, 0, 0.2);
+        -webkit-box-sizing: border-box;
+        -moz-box-sizing: border-box;
+        -ms-box-sizing: border-box;
+        -o-box-sizing: border-box;
+        box-sizing: border-box;
+        -webkit-font-smoothing: antialiased;
+        -moz-font-smoothing: antialiased;
+        -ms-font-smoothing: antialiased;
+        -o-font-smoothing: antialiased;
+        font-smoothing: antialiased;
+}
+
+#new-todo {
+        padding: 16px 16px 16px 60px;
+        border: none;
+        background: rgba(0, 0, 0, 0.02);
+        z-index: 2;
+        box-shadow: none;
+}
+
+#main {
+        position: relative;
+        z-index: 2;
+        border-top: 1px dotted #adadad;
+}
+
+label[for='toggle-all'] {
+        display: none;
+}
+
+#toggle-all {
+        position: absolute;
+        top: -42px;
+        left: -4px;
+        width: 40px;
+        text-align: center;
+        border: none; /* Mobile Safari */
+}
+
+#toggle-all:before {
+        content: '»';
+        font-size: 28px;
+        color: #d9d9d9;
+        padding: 0 25px 7px;
+}
+
+#toggle-all:checked:before {
+        color: #737373;
+}
+
+#todo-list {
+        margin: 0;
+        padding: 0;
+        list-style: none;
+}
+
+#todo-list li {
+        position: relative;
+        font-size: 24px;
+        border-bottom: 1px dotted #ccc;
+}
+
+#todo-list li:last-child {
+        border-bottom: none;
+}
+
+#todo-list li.editing {
+        border-bottom: none;
+        padding: 0;
+}
+
+#footer {
+        color: #777;
+        padding: 0 15px;
+        position: absolute;
+        right: 0;
+        bottom: -31px;
+        left: 0;
+        height: 20px;
+        z-index: 1;
+        text-align: center;
+}
+
+#footer:before {
+        content: '';
+        position: absolute;
+        right: 0;
+        bottom: 31px;
+        left: 0;
+        height: 50px;
+        z-index: -1;
+        box-shadow: 0 1px 1px rgba(0, 0, 0, 0.3),
+                                0 6px 0 -3px rgba(255, 255, 255, 0.8),
+                                0 7px 1px -3px rgba(0, 0, 0, 0.3),
+                                0 43px 0 -6px rgba(255, 255, 255, 0.8),
+                                0 44px 2px -6px rgba(0, 0, 0, 0.2);
+}
+
+#todo-count {
+        float: left;
+        text-align: left;
+}
+
+#filters {
+        margin: 0;
+        padding: 0;
+        list-style: none;
+        position: absolute;
+        right: 0;
+        left: 0;
+}
+
+#filters li {
+        display: inline;
+}
+
+#filters li a {
+        color: #83756f;
+        margin: 2px;
+        text-decoration: none;
+}
+
+#filters li.polymer-selected a {
+        font-weight: bold;
+}
+
+#clear-completed {
+        float: right;
+        position: relative;
+        line-height: 20px;
+        text-decoration: none;
+        background: rgba(0, 0, 0, 0.1);
+        font-size: 11px;
+        padding: 0 10px;
+        border-radius: 3px;
+        box-shadow: 0 -1px 0 0 rgba(0, 0, 0, 0.2);
+}
+
+#clear-completed:hover {
+        background: rgba(0, 0, 0, 0.15);
+        box-shadow: 0 -1px 0 0 rgba(0, 0, 0, 0.3);
+}
+
+@media screen and (-webkit-min-device-pixel-ratio:0) {
+        #toggle-all {
+                background: none;
+    /* 
+      ShadowDOM Polyfill work around for webkit/blink bug 
+      https://code.google.com/p/chromium/issues/detail?id=251510
+    */
+    background-color: transparent;
+        }
+
+        #toggle-all {
+                top: -56px;
+                left: -15px;
+                width: 65px;
+                height: 41px;
+                -webkit-transform: rotate(90deg);
+                transform: rotate(90deg);
+                -webkit-appearance: none;
+                appearance: none;
+        }
+}