Allow nullptr use in Chromium.

NOTRY=true

Review URL: https://codereview.chromium.org/600953002

Cr-Commit-Position: refs/heads/master@{#296509}

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

@@ -84,6 +84,18 @@ and <code>&lt;inttypes&gt;</code></td>
 <td>Already in common use in the codebase. Approved without discussion.</td>
 </tr>
 
+<tr>
+<td>Null Pointer Constant</td>
+<td><code>nullptr</code></td>
+<td>Declares a type-safe null pointer</td>
+<td>TODO: documentation link</td>
+<td>Recommended for new code.
+<a href="https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/4mijeJHzxLg">Discussion thread</a>.
+<a href="https://google-styleguide.googlecode.com/svn/trunk/cppguide.html#0_and_nullptr/NULL">Google Style Guide</a>.
+Note: <code>std::nullptr_t</code> is a library feature and not available.
+</td>
+</tr>
+
 </tbody>
 </table>
 
@@ -330,15 +342,6 @@ Non-static data members</a></td>
 <td></td>
 </tr>
 
-<tr>
-<td>Null Pointer Constant</td>
-<td><code>nullptr</code></td>
-<td>Declares a type-safe null pointer</td>
-<td>TODO: documentation link</td>
-<td><a href="https://google-styleguide.googlecode.com/svn/trunk/cppguide.html#0_and_nullptr/NULL">Google Style Guidwe</a>.
-</td>
-</tr>
-
 <tr>
 <td>Overrides</td>
 <td><code>override</code></td>