Add notes about CefLoadHandler methods/events being called on the CEF…

… UI thread and that blocking is not advised.

CefSharp/ILoadHandler.cs

@@ -4,45 +4,58 @@
 
 namespace CefSharp
 {
+    /// <summary>
+    /// Implement this interface to handle events related to browser load status.
+    /// The methods of this interface will be called on the CEF UI thread. Blocking in these methods
+    /// will likely cause your UI to become unresponsive and/or hang.
+    /// </summary>
     public interface ILoadHandler
     {
         /// <summary>
         /// Called when the loading state has changed. This callback will be executed twice
         /// once when loading is initiated either programmatically or by user action,
-        /// and once when loading is terminated due to completion, cancellation of failure. 
+        /// and once when loading is terminated due to completion, cancellation of failure.
+        /// This method will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         /// <param name="browserControl">The <see cref="IWebBrowser"/> control this popup is related to.</param>
         /// <param name="loadingStateChangedArgs">args</param>
         void OnLoadingStateChange(IWebBrowser browserControl, LoadingStateChangedEventArgs loadingStateChangedArgs);
 
         /// <summary>
         /// Called when the browser begins loading a frame.
-        /// The |<see cref="FrameLoadEndEventArgs.Frame"/> value will never be empty
+        /// The <see cref="FrameLoadEndEventArgs.Frame"/> value will never be empty
         /// Check the <see cref="IFrame.IsMain"/> method to see if this frame is the main frame.
         /// Multiple frames may be loading at the same time. Sub-frames may start or continue loading after the main frame load has ended.
         /// This method may not be called for a particular frame if the load request for that frame fails.
         /// For notification of overall browser load status use <see cref="OnLoadingStateChange"/> instead. 
+        /// This method will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         /// <param name="browserControl">The <see cref="IWebBrowser"/> control this popup is related to.</param>
         /// <param name="frameLoadStartArgs">args</param>
         void OnFrameLoadStart(IWebBrowser browserControl, FrameLoadStartEventArgs frameLoadStartArgs);
 
         /// <summary>
         /// Called when the browser is done loading a frame.
-        /// The |<see cref="FrameLoadEndEventArgs.Frame"/> value will never be empty
+        /// The <see cref="FrameLoadEndEventArgs.Frame"/> value will never be empty
         /// Check the <see cref="IFrame.IsMain"/> method to see if this frame is the main frame.
         /// Multiple frames may be loading at the same time. Sub-frames may start or continue loading after the main frame load has ended.
         /// This method will always be called for all frames irrespective of whether the request completes successfully. 
+        /// This method will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         /// <param name="browserControl">The <see cref="IWebBrowser"/> control this popup is related to.</param>
         /// <param name="frameLoadEndArgs">args</param>
         void OnFrameLoadEnd(IWebBrowser browserControl, FrameLoadEndEventArgs frameLoadEndArgs);
 
         /// <summary>
         /// Called when the resource load for a navigation fails or is canceled.
-        /// |errorCode| is the error code number, |errorText| is the error text and
-        /// |failedUrl| is the URL that failed to load. See net\base\net_error_list.h
+        /// <see cref="LoadErrorEventArgs.ErrorCode"/> is the error code number, <see cref="LoadErrorEventArgs.ErrorText"/> is the error text and
+        /// <see cref="LoadErrorEventArgs.FailedUrl"/> is the URL that failed to load. See net\base\net_error_list.h
         /// for complete descriptions of the error codes.
+        /// This method will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         /// <param name="browserControl">The <see cref="IWebBrowser"/> control this popup is related to.</param>
         /// <param name="loadErrorArgs">args</param>

CefSharp/IWebBrowser.cs

@@ -23,25 +23,33 @@ public interface IWebBrowser : IDisposable
         /// time. Sub-frames may start or continue loading after the main frame load has ended. This method may not be called for a
         /// particular frame if the load request for that frame fails. For notification of overall browser load status use
         /// OnLoadingStateChange instead.
+        /// This event will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         event EventHandler<FrameLoadStartEventArgs> FrameLoadStart;
 
         /// <summary>
         /// Event handler that will get called when the browser is done loading a frame. Multiple frames may be loading at the same
         /// time. Sub-frames may start or continue loading after the main frame load has ended. This method will always be called
         /// for all frames irrespective of whether the request completes successfully.
+        /// This event will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         event EventHandler<FrameLoadEndEventArgs> FrameLoadEnd;
 
         /// <summary>
         /// Event handler that will get called when the resource load for a navigation fails or is canceled.
+        /// This event will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         event EventHandler<LoadErrorEventArgs> LoadError;
 
         /// <summary>
         /// Event handler that will get called when the Loading state has changed.
         /// This event will be fired twice. Once when loading is initiated either programmatically or
         /// by user action, and once when loading is terminated due to completion, cancellation of failure. 
+        /// This event will be called on the CEF UI thread.
+        /// Blocking this thread will likely cause your UI to become unresponsive and/or hang.
         /// </summary>
         event EventHandler<LoadingStateChangedEventArgs> LoadingStateChanged;