Move std::unique_ptr to the C++11 allowed library features section.

BUG=554298

Review URL: https://codereview.chromium.org/1855113002

Cr-Commit-Position: refs/heads/master@{#384838}

Author: zetafunction

styleguide/c++/c++11.html

@@ -467,6 +467,16 @@ <h2 id="whitelist"><a name="library-whitelist"></a>C++11 Allowed Library Feature
 <td>Note that not all type traits are available on all platforms (eg std::underlying_type doesn't work in libstdc++4.6). Use judiciously. <a href='https://groups.google.com/a/chromium.org/forum/#!topic/cxx/vCxo4tZNd_M'>Discussion thread</a></td>
 </tr>
 
+<tr>
+<td>Tuples</td>
+<td><code>std::tuple</code></td>
+<td>A fixed-size ordered collection of values of mixed types</td>
+<td><a href="http://en.cppreference.com/w/cpp/utility/tuple">std::tuple</a></td>
+<td><a href="https://crbug.com/554987">Tracking bug</a> to plan moving from <code>base::Tuple</code> to <code>std::tuple</code>. See also <code>std::tie</code>.
+<code>base::Tuple</code> is now an alias for <code>std::tuple</code>. In class template specializations, use <code>std::tuple</code> instead of <code>base::Tuple</code> to work around a MSVS2013 internal compiler error (Error code: C1001).
+</td>
+</tr>
+
 <tr>
 <td>Unordered Associative Containers</td>
 <td><code>std::unordered_set</code>, <code>std::unordered_map</code>,
@@ -479,13 +489,11 @@ <h2 id="whitelist"><a name="library-whitelist"></a>C++11 Allowed Library Feature
 </tr>
 
 <tr>
-<td>Tuples</td>
-<td><code>std::tuple</code></td>
-<td>A fixed-size ordered collection of values of mixed types</td>
-<td><a href="http://en.cppreference.com/w/cpp/utility/tuple">std::tuple</a></td>
-<td><a href="https://crbug.com/554987">Tracking bug</a> to plan moving from <code>base::Tuple</code> to <code>std::tuple</code>. See also <code>std::tie</code>.
-<code>base::Tuple</code> is now an alias for <code>std::tuple</code>. In class template specializations, use <code>std::tuple</code> instead of <code>base::Tuple</code> to work around a MSVS2013 internal compiler error (Error code: C1001).
-</td>
+<td>Unique Pointers</td>
+<td><code>std::unique_ptr&lt;<i>type</i>&gt;</code></td>
+<td>A smart pointer with sole ownership of the owned object.</td>
+<td><a href="http://en.cppreference.com/w/cpp/memory/unique_ptr">std::unique_ptr</a></td>
+<td>Google style guide: <a href="https://google.github.io/styleguide/cppguide.html#Ownership_and_Smart_Pointers">Ownership and Smart Pointers</a>. <a href="https://groups.google.com/a/chromium.org/d/msg/cxx/aT2wsBLKvzI/oZuZ718oAwAJ">Discussion thread</a>. Use in all newly written code. scoped_ptr is a <a href="https://groups.google.com/a/chromium.org/d/msg/chromium-dev/roY78iTblYc/bb8nYsxfCgAJ">typedef for std::unique_ptr</a> and is going away shortly.</td>
 </tr>
 
 </tbody>
@@ -1059,15 +1067,6 @@ <h3 id="blacklist_stdlib_review"><a name="library-review"></a>C++11 Standard Lib
 within both associative and unordered containers</td>
 </tr>
 
-<tr>
-<td>Unique Pointers</td>
-<td><code>std::unique_ptr&lt;<i>type</i>&gt;</code></td>
-<td>Defines a pointer with clear and unambiguous ownership</td>
-<td>TODO: documentation link</td>
-<td><a href="https://google.github.io/styleguide/cppguide.html#Ownership_and_Smart_Pointers">
-Ownership and Smart Pointers</a></td>
-</tr>
-
 <tr>
 <td>Variadic Copy Macro</td>
 <td><code>va_copy(va_list <i>dest</i>, va_list <i>src</i>)</code></td>