Add pub logo in front of breadcrumbs.

Author: isoos

app/lib/dartdoc/customization.dart

@@ -29,11 +29,24 @@ class DartdocCustomizer {
     final doc = html_parser.parse(html);
     final breadcrumbs = doc.body.querySelector('.breadcrumbs');
     if (breadcrumbs != null) {
+      _addPubSiteLogo(breadcrumbs);
       _addPubPackageLink(breadcrumbs);
     }
     return doc.outerHtml;
   }
 
+  void _addPubSiteLogo(Element breadcrumbs) {
+    final parent = breadcrumbs.parent;
+    final logoLink = new Element.tag('a');
+    logoLink.attributes['href'] = 'https://pub.dartlang.org/';
+    final imgRef = new Element.tag('img');
+    imgRef.attributes['src'] = 'https://pub.dartlang.org/static/img/dart-logo.svg';
+    imgRef.attributes['style'] = 'height: 30px; margin-right: 1em;';
+    logoLink.append(imgRef);
+    parent.insertBefore(logoLink, breadcrumbs);
+    parent.insertBefore(new Text('\n  '), breadcrumbs);
+  }
+
   void _addPubPackageLink(Element breadcrumbs) {
     final pubPackageLink =
         'https://pub.dartlang.org/packages/$packageName/versions/$packageVersion';

app/test/dartdoc/golden/pana_0.10.2_index.out.html

@@ -19,6 +19,7 @@
 <div id="overlay-under-drawer"></div>
 
 <header id="title">
+  <a href="https://pub.dartlang.org/"><img src="https://pub.dartlang.org/static/img/dart-logo.svg" style="height: 30px; margin-right: 1em;"></a>
   <ol class="breadcrumbs gt-separated dark hidden-xs">
     <li><a href="https://pub.dartlang.org/packages/pana/versions/0.10.2">pana package</a></li>
   </ol>

app/test/dartdoc/golden/pana_0.10.2_license_file_class.out.html

@@ -21,6 +21,7 @@
 
 <header id="title">
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
+  <a href="https://pub.dartlang.org/"><img src="https://pub.dartlang.org/static/img/dart-logo.svg" style="height: 30px; margin-right: 1em;"></a>
   <ol class="breadcrumbs gt-separated dark hidden-xs">
     <li><a href="https://pub.dartlang.org/packages/pana/versions/0.10.2">pana package</a></li>
     <li><a href="index.html">documentation</a></li>

app/test/dartdoc/golden/pana_0.10.2_license_file_constructor.out.html

@@ -21,6 +21,7 @@
 
 <header id="title">
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
+  <a href="https://pub.dartlang.org/"><img src="https://pub.dartlang.org/static/img/dart-logo.svg" style="height: 30px; margin-right: 1em;"></a>
   <ol class="breadcrumbs gt-separated dark hidden-xs">
     <li><a href="https://pub.dartlang.org/packages/pana/versions/0.10.2">pana package</a></li>
     <li><a href="index.html">documentation</a></li>

app/test/dartdoc/golden/pana_0.10.2_license_file_name_field.out.html

@@ -21,6 +21,7 @@
 
 <header id="title">
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
+  <a href="https://pub.dartlang.org/"><img src="https://pub.dartlang.org/static/img/dart-logo.svg" style="height: 30px; margin-right: 1em;"></a>
   <ol class="breadcrumbs gt-separated dark hidden-xs">
     <li><a href="https://pub.dartlang.org/packages/pana/versions/0.10.2">pana package</a></li>
     <li><a href="index.html">documentation</a></li>

app/test/dartdoc/golden/pana_0.10.2_pretty_json.out.html

@@ -21,6 +21,7 @@
 
 <header id="title">
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
+  <a href="https://pub.dartlang.org/"><img src="https://pub.dartlang.org/static/img/dart-logo.svg" style="height: 30px; margin-right: 1em;"></a>
   <ol class="breadcrumbs gt-separated dark hidden-xs">
     <li><a href="https://pub.dartlang.org/packages/pana/versions/0.10.2">pana package</a></li>
     <li><a href="index.html">documentation</a></li>