libcef: Update due to underlying chromium changes.

- External plugin loading support is now provided by webkit/glue/plugins so the libcef/plugins directory has been eliminated, with related changes.
- Modify the CefPluginInfo structure to use a more friendly data organization format.
- Remove CefUnregisterPlugin() as it is no longer functional.
- WebViewDelegate::ShowContextMenu() now receives the menu type as a bit-masked flag, so adjust the API accordingly.
- WebViewDelegate::GetContainingView() now returns a gfx::NativeViewId instead of a gfx::NativeView.
- Modify BrowserRequestContext because GetUserAgent() is now a virtual method of URLRequestContext.
- The data buffer in RequestProxy is now a net::IOBuffer.
- Add webkit_glue::GetScreenInfo().

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@10 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser_webkit_glue.cc

@@ -167,4 +167,8 @@ bool IsLinkVisited(uint64 link_hash) {
   return false;
 }
 
+ScreenInfo GetScreenInfo(gfx::NativeViewId window) {
+  return GetScreenInfoHelper(gfx::NativeViewFromId(window));
+}
+
 }  // namespace webkit_glue