Update SystemCursorId

update from feedback

Author: jamesoli

specs/SystemCursorId

@@ -1,12 +1,12 @@
 # Background
 
-In visual hosting, the current cursor image cannot be determined easily by the
-hosting application easily. For example, if the cursor over the WebView is also
-over a textbox inside of the WebView, the cursor should usually be IDC_IBEAM.
-And by default, the cursor is IDC_ARROW. Currently, we return the what the
-cursor should be as an HCURSOR object (After calling LoadCursor on those IDC
-values). The hosting application can then use the HCURSOR object to change the
-current cursor to the correct image.
+When an app is using composition hosting to host WebView, the current cursor
+image cannot be determined easily by the hosting application. For example, if
+the cursor over the WebView is also over a textbox inside of the WebView, the
+cursor should usually be IDC_IBEAM. And by default, the cursor is IDC_ARROW.
+Currently, we return the what the cursor should be as an HCURSOR object (After
+calling LoadCursor on those IDC values). The hosting application can then use
+the HCURSOR object to change the current cursor to the correct image.
 
 However, Office already has a well established way of using cursors internally
 by using IDC_* values and there is no easy way to convert the HCURSOR object we
@@ -15,15 +15,21 @@ are returning into an IDC value after it's been created.
 This new API is to enable hosting applications like Office to get the current
 IDC value of the cursor instead of the HCURSOR as an option.
 
+Note that this is a COM and .NET spec as WinRT uses a separate enum structure to
+identify cursor IDs.
+
 
 # Description
 
-The `SystemCursorId` property will return the current system cursor ID reproted
+The `SystemCursorId` property will return the current system cursor ID reported
 by the underlying rendering engine for WebView2. It is not meant to return a
 value for any custom cursors, such as those defined by CSS.
 
 It can be used at any time but will only change after a `CursorChanged` event.
 
+Note that developers should generally use the `Cursor` property to support cases
+where there may be custom cursors.
+
 
 # Examples
 
@@ -59,12 +65,14 @@ CHECK_FAILURE(m_compositionController->add_CursorChanged(
 
 See [API Details](#api-details) section below for API reference.
 
+
 # API Details
 
+```cpp
 /// This interface is continuation of the 
-/// ICoreWebView2ExperimentalCompositionController interface.
+/// ICoreWebView2CompositionController interface.
 [uuid(279ae616-b7cb-4946-8da3-dc853645d2ba), object, pointer_default(unique)]
-interface ICoreWebView2ExperimentalCompositionController2 : IUnknown {
+interface ICoreWebView2CompositionController2 : ICoreWebView2CompositionController {
   /// The current system cursor ID reported by the underlying rendering engine
   /// for WebView. For example, most of the time, when the cursor is over text,
   /// this will return the int value for IDC_IBEAM. The systemCursorId is only
@@ -79,6 +87,33 @@ interface ICoreWebView2ExperimentalCompositionController2 : IUnknown {
   [propget] HRESULT SystemCursorId([out, retval] UINT32* systemCursorId);
 }
 
+```c#
+namespace Microsoft.Web.WebView2.Core
+{
+    //
+    // Summary:
+    //     This class is an extension of the CoreWebView2CompositionController class to support composition
+    //     hosting.
+    public class CoreWebView2CompositionController2 : CoreWebView2CompositionController
+    {
+        //
+        // Summary:
+        //     The current system cursor ID that WebView thinks it should be.
+        //
+        // Remarks:
+        //     The current system cursor ID reported by the underlying rendering engine
+        //     for WebView. For example, most of the time, when the cursor is over text,
+        //     this will return the int value for IDC_IBEAM. The SystemCursorId is only
+        //     valid if the rendering engine reports a default Windows cursor resource
+        //     value. See:
+        //     https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-loadcursorw
+        //     Otherwise, if custom CSS cursors are being used, this will return 0.
+        //     To create a Cursor object, create an IntPtr from the returned uint to
+        //     pass into the constructor
+        public Uint32 SystemCursorId { get; }
+    }
+}
+
 # Appendix
 
 I expect that most apps will use the get_Cursor API which returns an HCURSOR (Or