Fix mispelled words (#5058)

AArnott · web-flow · commit c30dcce362cc · 2020-11-08T14:43:12.000-08:00
diff --git a/xml/System.Diagnostics/DiagnosticSource.xml b/xml/System.Diagnostics/DiagnosticSource.xml
@@ -203,9 +203,9 @@ Note that `payload` is typed as an <xref:System.Object> here, but any particular
         <remarks>
           <format type="text/markdown"><![CDATA[  
 
-If an instrumentation site creates a new activity in response to some event outside the process, such as an incomming HTTP request), the `OnActivityImport` method allows that site will want to create a new activity and transfer state from the incoming request to the activity. 
+If an instrumentation site creates a new activity in response to some event outside the process, such as an incoming HTTP request), the `OnActivityImport` method allows that site will want to create a new activity and transfer state from the incoming request to the activity. 
 
-To the extent possible, this should be done by the instrumentation site, because there is a contract between the <xref:System.Diagnostics.Activity> and the incomming request logic at the instrumentation site.   However, the instrumentation site can't handle policy. (For example, if sampling is done, exactly which requests should be sampled?) In these cases, the instrumentation site needs to call back out to the logging system and ask it to resolve policy (for example, to decide if the activity's "sampling" bit should be set). This is the purpose of the `OnActivityImport` method. It is given the activity as well as a payload object that represents the incomming request. The subscribers to the <xref:System.Diagnostics.DiagnosticSource> then have the opportunity to update this activity as desired. 
+To the extent possible, this should be done by the instrumentation site, because there is a contract between the <xref:System.Diagnostics.Activity> and the incoming request logic at the instrumentation site.   However, the instrumentation site can't handle policy. (For example, if sampling is done, exactly which requests should be sampled?) In these cases, the instrumentation site needs to call back out to the logging system and ask it to resolve policy (for example, to decide if the activity's "sampling" bit should be set). This is the purpose of the `OnActivityImport` method. It is given the activity as well as a payload object that represents the incoming request. The subscribers to the <xref:System.Diagnostics.DiagnosticSource> then have the opportunity to update this activity as desired. 
 
 This method is rarely used at instrumentation sites (only those sites that are on the boundary of the process), and the instrumetation site implements some default policy (it sets the activity in *some* way), and so it is not necessary to override this method if that default policy is fine. In other words, this method should be overridden in very rare (but often important) cases.
 
