Merge remote-tracking branch 'remotes/upstream/master' into feature/winforms-tabbed

Author: amaitland

CefSharp.WinForms/CefSharp.WinForms.csproj

@@ -42,6 +42,7 @@
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Drawing" />
     <Reference Include="System.Windows.Forms" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />

CefSharp.WinForms/ChromiumWebBrowser.cs

@@ -140,7 +140,9 @@ protected override void OnHandleCreated(EventArgs e)
         protected override void OnSizeChanged(EventArgs e)
         {
             base.OnSizeChanged(e);
-            if (managedCefBrowserAdapter != null)
+
+            // Size is 0x0 when we are on a modeless Form which is minimized.
+            if (!Size.IsEmpty && managedCefBrowserAdapter != null)
                 managedCefBrowserAdapter.OnSizeChanged(Handle);
         }