Add a notice about other forms of history to the CBD dialog

chrome/browser/resources/options/clear_browser_data_overlay.css

 /* Copyright (c) 2012 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. */
 
 #clear-browser-data-overlay {
   width: 500px;
 }
 
 #clear-data-checkboxes {
   -webkit-padding-start: 8px;
@@ skipping 30 matching lines @@
 }
 
 input[type=checkbox]:not(:checked) ~ .clear-browser-data-counter {
   display: none;
 }
 
 #clear-browser-data-info-banner:empty {
   display: none;
 }
 
+#some-stuff-remains-footer {
+  display: block;
+}
+
 #some-stuff-remains-footer > p {
-  margin: 0;
+  -webkit-padding-start: 33px;
 }
 
 #some-stuff-remains-footer button {
   padding: 0;
 }
+
+#clear-browser-data-history-footer {
+  background-image: url(googleg.svg);
+  background-position: left center;

[Dan Beam, 2016/03/31 04:47:00]

what extra space is there? I.e. why do you need the "left" here that has to be
mirrored rather than use a different mechanism?

[msramek, 2016/03/31 18:19:56]

The footer also contains text (starting at -webkit-padding-start: 33px defined
above). The image is positioned inside that padding (i.e. left by default and
right in RTL).

+  background-repeat: no-repeat;

[Dan Beam, 2016/03/31 04:47:00]

nit: background shorthand

[msramek, 2016/03/31 18:19:56]

Done.

+  background-size: 16px 16px;
+  margin: 0 0 0.8em 0;
+  min-height: 16px;

[msramek, 2016/03/21 16:30:25]

Since the icons are only in the background, I added min-height to make sure that
the <p> element is always large enough. It shouldn't be necessary, as the
default line height is 21px, but it doesn't hurt either.

+}
+
+#clear-browser-data-general-footer {
+  background-image: url(info.svg);
+  background-position: left center;
+  background-repeat: no-repeat;
+  background-size: 18px 18px;
+  margin: 0;
+  min-height: 18px;
+}
+
+html[dir='rtl'] #clear-browser-data-history-footer,
+html[dir='rtl'] #clear-browser-data-general-footer {
+  background-position: right center;
+}
+
+#clear-browser-data-history-notice {
+  width: 300px;
+}