Cef.h - Remove ThrowIfCefNotInitialized

As IsInitialized is set when CefInitialize returns and it appears to be possible the OnContextInitialized is called
before it returns then this exception wasn't going to work.

Testing with Cef.GetGlobalRequestContext and Cef.GetGlobalCookieManager and they both return null if called before Cef.Initialize
So it shouldn't be possible to actually access the cookie manager/RequestContext. Improved the xml doc

Resolves #2600

Author: amaitland

CefSharp.Core/Cef.h

@@ -32,8 +32,6 @@ namespace CefSharp
 {
     public ref class Cef sealed
     {
-        #define ThrowIfCefNotInitialized() if (!_initialized) throw gcnew Exception(__FUNCTION__ + " requires that CefRequestContext be initialized first. The earlier possible place to execute " + __FUNCTION__ + " is in IBrowserProcessHandler.OnContextInitialized. Alternative use the ChromiumWebBrowser BrowserInitialized (OffScreen) or IsBrowserInitializedChanged (WinForms/WPF) events.");
-
     private:
         static Object^ _sync;
 
@@ -324,8 +322,6 @@ namespace CefSharp
             String^ targetDomain,
             bool allowTargetSubdomains)
         {
-            //ThrowIfCefNotInitialized();
-
             return CefAddCrossOriginWhitelistEntry(
                 StringUtils::ToNative(sourceOrigin),
                 StringUtils::ToNative(targetProtocol),
@@ -350,8 +346,6 @@ namespace CefSharp
             bool allowTargetSubdomains)
 
         {
-            //ThrowIfCefNotInitialized();
-
             return CefRemoveCrossOriginWhitelistEntry(
                 StringUtils::ToNative(sourceOrigin),
                 StringUtils::ToNative(targetProtocol),
@@ -366,24 +360,24 @@ namespace CefSharp
         /// </remarks>
         static bool ClearCrossOriginWhitelist()
         {
-            //ThrowIfCefNotInitialized();
-
             return CefClearCrossOriginWhitelist();
         }
 
         /// <summary>
-        /// Returns the global cookie manager.
+        /// Returns the global cookie manager. By default data will be stored at CefSettings.CachePath if specified or in memory otherwise.
+        /// Using this method is equivalent to calling Cef.GetGlobalRequestContext().GetDefaultCookieManager()
+        /// The earlier possible place to access the ICookieManager is in IBrowserProcessHandler.OnContextInitialized.
+        /// Alternative use the ChromiumWebBrowser BrowserInitialized (OffScreen) or IsBrowserInitializedChanged (WinForms/WPF) events.
         /// </summary>
-        /// <returns>A the global cookie manager</returns>
+        /// <returns>A the global cookie manager or null if the RequestContext has not yet been initialized.</returns>
         static ICookieManager^ GetGlobalCookieManager()
         {
-            //ThrowIfCefNotInitialized();
-
             auto cookieManager = CefCookieManager::GetGlobalManager(NULL);
             if (cookieManager.get())
             {
                 return gcnew CookieManager(cookieManager);
             }
+
             return nullptr;
         }
 
@@ -398,13 +392,12 @@ namespace CefSharp
         /// <returns>A blocking cookie manager</returns>
         static ICookieManager^ GetBlockingCookieManager()
         {
-            //ThrowIfCefNotInitialized();
-
             auto cookieManager = CefCookieManager::GetBlockingManager();
             if (cookieManager.get())
             {
                 return gcnew CookieManager(cookieManager);
             }
+
             return nullptr;
         }
 
@@ -488,13 +481,13 @@ namespace CefSharp
         }
 
         /// <summary>
-        /// Clear all registered scheme handler factories.
+        /// Clear all scheme handler factories registered with the global request context.
+        /// Returns false on error. This function may be called on any thread in the browser process.
+        /// Using this function is equivalent to calling Cef.GetGlobalRequestContext().ClearSchemeHandlerFactories().
         /// </summary>
         /// <returns>Returns false on error.</returns>
         static bool ClearSchemeHandlerFactories()
         {
-            //ThrowIfCefNotInitialized();
-
             return CefClearSchemeHandlerFactories();
         }
 
@@ -503,8 +496,6 @@ namespace CefSharp
         /// </summary>
         static void VisitWebPluginInfo(IWebPluginInfoVisitor^ visitor)
         {
-            //ThrowIfCefNotInitialized();
-
             CefVisitWebPluginInfo(new PluginVisitor(visitor));
         }
 
@@ -515,8 +506,6 @@ namespace CefSharp
         /// <returns>Returns List of <see cref="Plugin"/> structs.</returns>
         static Task<List<WebPluginInfo^>^>^ GetPlugins()
         {
-            //ThrowIfCefNotInitialized();
-
             auto taskVisitor = gcnew TaskWebPluginInfoVisitor();
             CefRefPtr<PluginVisitor> visitor = new PluginVisitor(taskVisitor);
 
@@ -530,8 +519,6 @@ namespace CefSharp
         /// </summary>
         static void RefreshWebPlugins()
         {
-            //ThrowIfCefNotInitialized();
-
             CefRefreshWebPlugins();
         }
 
@@ -541,8 +528,6 @@ namespace CefSharp
         /// <param name="path">Path (directory + file).</param>
         static void UnregisterInternalWebPlugin(String^ path)
         {
-            //ThrowIfCefNotInitialized();
-
             CefUnregisterInternalWebPlugin(StringUtils::ToNative(path));
         }
 
@@ -567,12 +552,12 @@ namespace CefSharp
 
         /// <summary>
         /// Gets the Global Request Context. Make sure to Dispose of this object when finished.
+        /// The earlier possible place to access the IRequestContext is in IBrowserProcessHandler.OnContextInitialized.
+        /// Alternative use the ChromiumWebBrowser BrowserInitialized (OffScreen) or IsBrowserInitializedChanged (WinForms/WPF) events.
         /// </summary>
-        /// <returns>Returns the global request context or null.</returns>
+        /// <returns>Returns the global request context or null if the RequestContext has not been initialized yet.</returns>
         static IRequestContext^ GetGlobalRequestContext()
         {
-            //ThrowIfCefNotInitialized();
-
             auto context = CefRequestContext::GetGlobalContext();
 
             if (context.get())