Add remarks on disposable ctor parameter to System.Net.Http.StreamCon… (#3357)

* Add remarks on disposable ctor parameter to System.Net.Http.StreamContent (#3339)

Author: JJS

xml/System.Net.Http/StreamContent.xml

@@ -73,7 +73,15 @@
       <Docs>
         <param name="content">The content used to initialize the <see cref="T:System.Net.Http.StreamContent" />.</param>
         <summary>Creates a new instance of the <see cref="T:System.Net.Http.StreamContent" /> class.</summary>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks
+
+The <xref:System.Net.Http.StreamContent> object calls <xref:System.IO.Stream.Dispose> on the provided <xref:System.IO.Stream> object when <xref:System.Net.Http.StreamContent.Dispose%2A?displayProperty=nameWithType> is called.
+
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName=".ctor">
@@ -107,7 +115,14 @@
         <param name="content">The content used to initialize the <see cref="T:System.Net.Http.StreamContent" />.</param>
         <param name="bufferSize">The size, in bytes, of the buffer for the <see cref="T:System.Net.Http.StreamContent" />.</param>
         <summary>Creates a new instance of the <see cref="T:System.Net.Http.StreamContent" /> class.</summary>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+The <xref:System.Net.Http.StreamContent> object calls <xref:System.IO.Stream.Dispose> on the provided <xref:System.IO.Stream> object when <xref:System.Net.Http.StreamContent.Dispose%2A?displayProperty=nameWithType> is called.
+  
+ ]]></format>
+        </remarks>
         <exception cref="T:System.ArgumentNullException">The <paramref name="content" /> was <see langword="null" />.</exception>
         <exception cref="T:System.ArgumentOutOfRangeException">The <paramref name="bufferSize" /> was less than or equal to zero.</exception>
       </Docs>