Add support for transparency on Windows (issue #99).

- Enable the use of Skia instead of GDI for text rendering.
- Add a new CefWindowInfo::m_bTransparentPainting member.
- Add transparent popup window and off-screen rendering examples to cefclient.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@334 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/internal/cef_types_win.h

@@ -74,6 +74,9 @@ typedef struct _cef_window_info_t
   // |m_hWndParent| to the window that will act as the parent for popup menus,
   // dialog boxes, etc.
   BOOL m_bWindowRenderingDisabled;
+
+  // Set to true to enable transparent painting.
+  BOOL m_bTransparentPainting;
   
   // Handle for the new browser window.
   cef_window_handle_t m_hWnd;

include/internal/cef_win.h

@@ -99,6 +99,7 @@ struct CefWindowInfoTraits {
     target->m_hWndParent = src->m_hWndParent;
     target->m_hMenu = src->m_hMenu;
     target->m_bWindowRenderingDisabled = src->m_bWindowRenderingDisabled;
+    target->m_bTransparentPainting = src->m_bTransparentPainting;
     target->m_hWnd = src->m_hWnd;
   }
 };
@@ -144,6 +145,11 @@ public:
     m_bWindowRenderingDisabled = TRUE;
     m_hWndParent = hWndParent;
   }
+
+  void SetTransparentPainting(BOOL transparentPainting)
+  {
+    m_bTransparentPainting = transparentPainting;
+  }
 };