Doc change: add v7 mediarouter lib to index and feature summary, with preview notice.

Change-Id: I23e4bdec971a982f545c4118b5c154a8949170cf
(cherry picked from commit a32db2f12d2eae0440b575bfd006ee83967ef61c)

docs/html/tools/support-library/features.jd

@@ -12,6 +12,7 @@ page.title=Support Library Features
         <ol>
           <li><a href="#v7-appcompat">v7 appcompat library</a></li>
           <li><a href="#v7-gridlayout">v7 gridlayout library</a></li>
+          <li><a href="#v7-mediarouter">v7 mediarouter library</a></li>
         </ol>
       </li>
       <li><a href="#v13">v13 Support Library</a></li>
@@ -148,7 +149,6 @@ com.android.support:support-v4:18.0.+
 <p>This dependency notation specifies the release version 18.0.0 or higher.</p>
 
 
-
 <h2 id="v7">v7 Libraries</h2>
 
 <p>There are several libraries designed to be used with Android 2.1 (API level 7) and higher.
@@ -197,9 +197,7 @@ com.android.support:support-v4:18.0.+
 com.android.support:appcompat-v7:18.0.+
 </pre>
 
-<p>This dependency notation specifies release version 18.0.0 or higher.</p>
-
-
+<p>This dependency notation specifies the release version 18.0.0 or higher.</p>
 
 <h3 id="v7-gridlayout">v7 gridlayout library</h3>
 
@@ -220,7 +218,48 @@ com.android.support:appcompat-v7:18.0.+
 com.android.support:gridlayout-v7:18.0.+
 </pre>
 
-<p>This dependency notation specifies release version 18.0.0 or higher.</p>
+<p>This dependency notation specifies the release version 18.0.0 or higher.</p>
+
+<h3 id="v7-mediarouter">v7 mediarouter library</h3>
+
+<p>This library provides {@link android.support.v7.media.MediaRouter}, {@link
+android.support.v7.media.MediaRouteProvider}, and related media classes that
+support the <a href="https://developers.google.com/cast/">Google Cast
+developer preview</a>. </p>
+
+<p>In general, the APIs in the v7 mediarouter library provide a means of
+controlling the routing of media channels and streams from the current device to
+external screens, speakers, and other destination devices. The library includes
+APIs for publishing app-specific media route providers, for discovering and
+selecting destination devices, for checking media status, and more. For detailed
+information about the v7 mediarouter library APIs, see the
+{@link android.support.v7.media android.support.v7.media} package in the API
+reference.</p>
+
+<p>The v7 mediarouter library is located in the
+<code>&lt;sdk&gt;/extras/android/support/v7/mediarouter/</code> directory after
+you download the Android Support Library. It's provided as a library project
+with a dependency on the v7 appcompat library, so you'll need to include both
+libraries in your build path when setting up your project. For more information
+on how to set up your project, follow the instructions in <a
+href="{@docRoot}tools/support-library/setup.html#libs-with-res">adding libraries
+with resources</a>. If you are developing in Eclipse/ADT, make sure to include
+both the <code>android-support-v7-mediarouter.jar</code> and
+<code>android-support-v7-appcompat.jar</code> files.</p>
+
+<p>If you are using Android Studio, all you need to do is specify the Gradle build
+script dependency identifier <code>com.android.support:support-v7-mediarouter:&lt;revision&gt;</code>,
+where "18.0.0" is the minimum revision at which the library is available. For example:</p>
+
+<pre>
+com.android.support:support-v7-mediarouter:18.0.0
+</pre>
+
+<p class="caution">The v7 mediarouter library APIs introduced in Support Library
+r18 are subject to change in later revisions of the Support Library. At this
+time, we recommend using the library only in connection with the <a
+href="https://developers.google.com/cast/">Google Cast
+developer preview</a>. </p>
 
 
 <h2 id="v13">v13 Support Library</h2>

docs/html/tools/support-library/index.jd

@@ -22,8 +22,7 @@ page.title=Support Library
   </div>
 </div>
 
-<p>The Android Support Library package is a set of code libraries that provide useful and important
-  features for Android applications in addition to the framework APIs. These libraries provide
+<p>The Android Support Library package is a set of code libraries that provide
   backward-compatible versions of Android framework APIs as well as features that are only available
   through the library APIs. Each Support Library is backward-compatible to a specific Android API
   level. This design means that your applications can use the libraries' features and still be
@@ -36,7 +35,8 @@ page.title=Support Library
 <h2 id="overview">Overview</h2>
 
 <p>Including the Support Libraries in your Android project is considered a best practice for
-  application developers. Using the features they provide can help you improve the look of your
+  application developers, depending on the range of platform versions your app is targeting
+  and the APIs that it uses. Using the features the libraries provide can help you improve the look of your
   application, increase performance and broaden the reach of your application to more users.
   If you use the Android
   <a href="{@docRoot}tools/projects/templates.html">code template</a> tools, you will notice that
@@ -136,6 +136,24 @@ page.title=Support Library
         </ul>
       </dd>
 
+      <dt>New v7 mediarouter library:</dt>
+      <dd>
+        <p>Added a new mediarouter library that provides support for the <a
+        href="https://developers.google.com/cast/">Google Cast developer preview</a>.
+        The v7 mediarouter library APIs provide a means of controlling the routing of
+        media channels and streams from the current device to external screens,
+        speakers, and other destination devices, with compatibility back to Android 2.1
+        (API level 7). See <a
+        href="{@docRoot}tools/support-library/features.html#v7-mediarouter">V7
+        mediarouter library</a> for more information. </p>
+
+        <p class="caution">The v7 mediarouter library APIs introduced in Support
+        Library r18 are subject to change in later revisions of the Support
+        Library. At this time, we recommend using the library only in connection
+        with the <a href="https://developers.google.com/cast/">Google Cast
+        developer preview</a>.</p>
+      </dd>
+
     </dl>
   </div>
 </div>