Add support for loading extensions (issue #1947)

- Add CefRequestContext::LoadExtension, CefExtension, CefExtensionHandler and
  related methods/interfaces.
- Add chrome://extensions-support that lists supported Chrome APIs.
- Add CefBrowserHost::SetAutoResizeEnabled and CefDisplayHandler::OnAutoResize
  to support browser resize based on preferred web contents size.
- views: Add support for custom CefMenuButton popups.
- cefclient: Run with `--load-extension=set_page_color` command-line flag for
  an extension loading example. Add `--use-views` on Windows and Linux for an
  even better example.

libcef_dll/cpptoc/display_handler_cpptoc.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=ae4395cea3553abdea6394d37325c40454505477$
+// $hash=b52f437f558356645aaf45ee20cf4f3983e03891$
 //
 
 #include "libcef_dll/cpptoc/display_handler_cpptoc.h"
@@ -184,6 +184,35 @@ display_handler_on_console_message(struct _cef_display_handler_t* self,
   return _retval;
 }
 
+int CEF_CALLBACK
+display_handler_on_auto_resize(struct _cef_display_handler_t* self,
+                               cef_browser_t* browser,
+                               const cef_size_t* new_size) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return 0;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return 0;
+  // Verify param: new_size; type: simple_byref_const
+  DCHECK(new_size);
+  if (!new_size)
+    return 0;
+
+  // Translate param: new_size; type: simple_byref_const
+  CefSize new_sizeVal = new_size ? *new_size : CefSize();
+
+  // Execute
+  bool _retval = CefDisplayHandlerCppToC::Get(self)->OnAutoResize(
+      CefBrowserCToCpp::Wrap(browser), new_sizeVal);
+
+  // Return type: bool
+  return _retval;
+}
+
 }  // namespace
 
 // CONSTRUCTOR - Do not edit by hand.
@@ -197,6 +226,7 @@ CefDisplayHandlerCppToC::CefDisplayHandlerCppToC() {
   GetStruct()->on_tooltip = display_handler_on_tooltip;
   GetStruct()->on_status_message = display_handler_on_status_message;
   GetStruct()->on_console_message = display_handler_on_console_message;
+  GetStruct()->on_auto_resize = display_handler_on_auto_resize;
 }
 
 template <>