Add context menu support (issue #509):

- Add new CefContextMenuHandler, CefContextMenuParams and CefMenuModel classes.
- Add cef_strings.grd and related infrastructure for supporting translation of CEF strings.
- Generate include/cef_pack_resources.h and include/cef_pack_strings.h files at build time that include all IDs used by CEF pack files.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@595 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser/browser_host_impl.cc

@@ -774,6 +774,13 @@ void CefBrowserHostImpl::LoadingStateChanged(content::WebContents* source) {
   }
 }
 
+bool CefBrowserHostImpl::HandleContextMenu(
+    const content::ContextMenuParams& params) {
+  if (!menu_creator_.get())
+    menu_creator_.reset(new CefMenuCreator(this));
+  return menu_creator_->CreateContextMenu(params);
+}
+
 bool CefBrowserHostImpl::ShouldCreateWebContents(
     content::WebContents* web_contents,
     int route_id,