add the 'reference only' header design as a condition to the normal templates.
also add override for implementation to the to-root link path.
bug: 27667787

Change-Id: I79892ddb7c5053d5325afcd50016c726b34e1361
diff --git a/tools/droiddoc/templates-sdk/components/masthead.cs b/tools/droiddoc/templates-sdk/components/masthead.cs
index 9db0466..8f98d0d 100644
--- a/tools/droiddoc/templates-sdk/components/masthead.cs
+++ b/tools/droiddoc/templates-sdk/components/masthead.cs
@@ -140,7 +140,7 @@
   </nav>
   <!-- end NDK navigation-->
   <?cs else ?>
-  <!-- Navigation-->
+  <!-- Standard DAC Navigation-->
   <nav class="dac-nav">
     <div class="dac-nav-dimmer" data-dac-toggle-nav></div>
 
@@ -151,8 +151,32 @@
                srcset="<?cs var:toroot ?>assets/images/android_logo@2x.png 2x"
                width="32" height="36" alt="Android" /> Developers
         </a>
+      </li><?cs
+      #
+      # For the reference only docs, include just one tab
+      #
+      ?><?cs if:referenceonly ?>
+      <li class="dac-nav-item develop">
+        <a class="dac-nav-link has-subnav" href="<?cs var:toroot ?>reference/packages.html" zh-tw-lang="參考資源"
+        zh-cn-lang="参考" ru-lang="Справочник" ko-lang="참조문서" ja-lang="リファレンス"
+        es-lang="Referencia">API Reference!!</a>
+      <div class="dac-nav-secondary develop">
+        <h1 style="font-size: 20px; line-height: 24px; margin: 20px; color:#444"
+          ><?cs
+          if:sdk.preview
+            ?>Android <?cs var:sdk.codename ?>
+              Preview <?cs var:sdk.preview.version ?><?cs
+          else
+            ?>Android <?cs var:sdk.version ?>
+              r<?cs var:sdk.rel.id ?><?cs
+          /if ?></h1>
+      </div>
       </li>
-      <li class="dac-nav-item home">
+      <?cs else ?><?cs
+      #
+      # End reference only docs, now the online DAC tabs...
+      #
+      ?><li class="dac-nav-item home">
         <a class="dac-nav-link dac-visible-mobile-block" href="<?cs var:toroot ?>index.html">Home</a>
         <ul class="dac-nav-secondary about">
           <li class="dac-nav-item about">
@@ -262,7 +286,12 @@
             <a class="dac-nav-link" href="<?cs var:toroot ?>distribute/stories/index.html">Stories</a>
           </li>
         </ul>
-      </li>
+      </li><?cs
+      /if ?><?cs
+      #
+      # End if/else reference only docs
+      #
+      ?>
     </ul>
   </nav>
   <!-- end navigation-->