Add Roboto-Medium webfont and factor out common Roboto WebUI CSS file.

ui/webui/resources/css/roboto.css

Index: ui/webui/resources/css/roboto.css
diff --git a/ui/webui/resources/css/roboto.css b/ui/webui/resources/css/roboto.css
new file mode 100644
index 0000000000000000000000000000000000000000..558593eae6d704ec7c0bb91256e59a12290ded85
--- /dev/null
+++ b/ui/webui/resources/css/roboto.css
@@ -0,0 +1,21 @@
+/* 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. */
+@font-face {

[michaelpg, 2015/05/19 03:21:57]

nit: newline above declaration block

[tsergeant, 2015/05/19 03:35:59]

Done.

+  font-family: 'Roboto';
+  font-style: normal;
+  font-weight: 400;
+  src: local('Roboto'), local('Roboto-Regular'),
+      url(chrome://resources/roboto/roboto-regular-latin.woff2) format('woff2');
+  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02C6, U+02DA, U+02DC,

[michaelpg, 2015/05/19 03:21:57]

this is a very different set than the other CSS files had. Can you explain where
these code points came from/why they're right?

[tsergeant, 2015/05/19 03:35:59]

The unicode-range from the old files was actually incorrect. These ranges both
came from the output of fonts.googleapis.com. Inspecting the old range shows
that it is Cyrillic (U+460, for example, maps to Ѡ), while U+0000-00FF (which
includes all of ASCII) from the new range is a good hint that it corresponds to
Latin.

[michaelpg, 2015/05/19 07:21:27]

Great, thanks for explaining. Glad to have this all in one place now.

+      U+2000-206F, U+2074, U+20AC, U+2212, U+2215, U+E0FF, U+EFFD, U+F000;
+}
+@font-face {

[michaelpg, 2015/05/19 03:21:57]

same nit

[tsergeant, 2015/05/19 03:35:59]

Done.

+  font-family: 'Roboto';
+  font-style: normal;
+  font-weight: 500;
+  src: local('Roboto Medium'), local('Roboto-Medium'),
+      url(chrome://resources/roboto/roboto-medium-latin.woff2) format('woff2');
+  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02C6, U+02DA, U+02DC,
+      U+2000-206F, U+2074, U+20AC, U+2212, U+2215, U+E0FF, U+EFFD, U+F000;
+}