Added more details on certain edge case scenarios

Updated the comments in the docs so updated comments here.

Author: mrsteamfist

specs/GetFavicon.md

@@ -1,11 +1,12 @@
 # Background
-A Favicon is an asset which is a part of a  webpage, and typically displayed on each tab. Developers would
-like to have an API which allows them to retrieve the Favicon of a webpage, if it has one, as well as get an update whenever
-the favicon has changed.
+A Favicon is an asset which is a part of a webpage, and typically displayed on each tab. Developers would
+like to have an API which allows them to retrieve the Favicon of a webpage, if it has been set, as well as get an update whenever the favicon has changed.
 
 # Description
 We propose a new Webview2 event which would allow developers access the current Favicon of a page, 
-as well as be notified when the favicon changes.
+as well as be notified when the favicon changes. This means when a page first loads, it would fire
+the Favicon change event as the icon has inialized to null. DOM or Javascript may change the Favicon,
+causing the event to fire again.
 
 # Examples
 ## Win32 C++ Registering a listener for favicon changes
@@ -53,52 +54,66 @@ webView.CoreWebView2.FaviconChanged += (CoreWebView2 sender, Object arg) =>
 };
 ```
 # API Notes
-If a Web page does not have a Favicon, then the event is not fired.
+If a Web page does not have a Favicon, then the event is only fires when the
+page is navigated to. The Favicon would be an empty image and Uri. The
+user is expected to handle this scenario.
 See [API Details](#api-details) Section below for API reference
 # API Details
 ## Win32 C++
 ```cpp
-/// Interface for the Favicon changed event handler
-[uuid(A0CDE626-8E5E-4EE2-9766-58F3696978FE), object, pointer_default(unique)]
-interface ICoreWebView2FaviconChangedEventHandler : IUnknown {
-  /// Called to provide the implementer with the event args for the
-  /// corresponding event.
+/// This interface is a handler for when the `Favicon` is changed.
+/// The sender is the embedded_browser which handle the change and the
+/// second argument is null.
+/// For more information see `add_FaviconChanged`.
+[uuid(2913DA94-833D-4DE0-8DCA-900FC524A1A4), object, pointer_default(unique)]
+interface ICoreWebView2ExperimentalFaviconChangedEventHandler : IUnknown {
+  /// Called to notify the favicon changed.
   HRESULT Invoke(
       [in] ICoreWebView2* sender,
       [in] IUnknown* args);
 }
 
-[uuid(93ACC5AD-DC22-419E-9A3F-75D96A1538E4), object, pointer_default(unique)]
-interface ICoreWebView2GetFaviconCompletedHandler : IUnknown {
-  /// Called to provide the implementer with the completion information of CoreWebView2.GetFaviconAsync.
-  /// corresponding event.
+/// This interface is a handler for the completion of the copying for the`imageStream`.
+/// The 'error_code` is E_NOT_SET if the there is no image. Otherwise error_code 
+/// is the result from the image write operation.
+/// For more details, see the `GetFavicon` API.
+[uuid(A2508329-7DA8-49D7-8C05-FA125E4AEE8D), object, pointer_default(unique)]
+interface ICoreWebView2ExperimentalGetFaviconCompletedHandler : IUnknown {
+  /// Called to notify the favicon has been retrieved.
   HRESULT Invoke([in] HRESULT error_code);
 }
 
+/// This is the ICoreWebView2 Experimental Favicon interface.
+/// It has the capability to fire an event for the changing of the
+/// Favicon. When a new page loads event would fire due to Favicon not being set.
+/// The event would also set the Favicon when the set by DOM or Javascript.
 [uuid(DC838C64-F64B-4DC7-98EC-0992108E2157), object, pointer_default(unique)]
 interface ICoreWebView2_10 : ICoreWebView2_9 {
-  /// Add an event handler for the `FaviconChanged` event.
-  /// `FaviconChanged` is raised when the favicon of the top-level document of the WebView2 changes.
-  HRESULT add_FaviconChanged(
-        [in] ICoreWebView2FaviconChangedEventHandler* eventHandler,
+    /// Add an event handler for the `FaviconChanged` event.
+    HRESULT add_FaviconChanged(
+        [in] ICoreWebView2ExperimentalFaviconChangedEventHandler* eventHandler,
         [out] EventRegistrationToken* token);
 
-  /// Remove an event handler from the `FaviconChanged` event.
-  HRESULT remove_FaviconChanged(
-      [in] EventRegistrationToken token);
-
-/// Async function for getting the actual image data of the favicon
- HRESULT GetFaviconAsync(
+    /// Remove the event handler for `FaviconChanged` event.
+    HRESULT remove_FaviconChanged(
+        [in] EventRegistrationToken token);
+
+    /// Get the current Uri of the favicon.
+    /// If value is null, the `HRESULT` `E_POINTER`, otherwise it is `S_OK`.
+    /// If a page has no favicon then value is an empty string.
+    [propget] HRESULT FaviconUri([out, retval] LPWSTR* value);
+
+    /// Async function for getting the actual image data of the favicon.
+    /// If the `imageStream` is null, the `HRESULT` will be `E_POINTER`, otherwise
+    /// it is `S_OK`.
+    /// The image is copied to the `imageStream` object and when complete,
+    /// it will execute the `eventHandler` if it was set.
+    HRESULT GetFavicon(
         [in] COREWEBVIEW2_FAVICON_IMAGE_FORMAT format,
-        [in] IStream * imageStream,
-        [in] ICoreWebView2GetFaviconCompletedHandler* eventHandler
- );
-
-  /// Used to access the current value of the favicon's URI.
-  /// If a page has no favicon then this returns a nullptr.
-  [propget] HRESULT FaviconUri([out, retval] LPWSTR* value);
-
+        [in] IStream* imageStream,
+        [in] ICoreWebView2ExperimentalGetFaviconCompletedHandler* eventHandler);
 }
+
 [v1_enum]
 typedef enum COREWEBVIEW2_FAVICON_IMAGE_FORMAT {
     /// Indicates that CoreWebView2.GetFaviconAsync should return the favicon in PNG format.