Implement autosizing for <extensionoptions>

chrome/browser/guest_view/extension_options/extension_options_guest.cc

Index: chrome/browser/guest_view/extension_options/extension_options_guest.cc
diff --git a/chrome/browser/guest_view/extension_options/extension_options_guest.cc b/chrome/browser/guest_view/extension_options/extension_options_guest.cc
index 3c8c4f5666259bf073bae23f9ecff3a27a6843c4..915b87c41ea383b3a76cc81b2ed4e0f9c3ef31cf 100644
--- a/chrome/browser/guest_view/extension_options/extension_options_guest.cc
+++ b/chrome/browser/guest_view/extension_options/extension_options_guest.cc
@@ -22,6 +22,7 @@
 #include "ipc/ipc_message_macros.h"
 
 using content::WebContents;
+using namespace extensions::api;
 
 // static
 const char ExtensionOptionsGuest::Type[] = "extensionoptions";
@@ -138,3 +139,12 @@ void ExtensionOptionsGuest::OnRequest(
   extension_function_dispatcher_->Dispatch(
       params, guest_web_contents()->GetRenderViewHost());
 }
+
+void ExtensionOptionsGuest::SizeChanged(const gfx::Size& old_size,
+                                        const gfx::Size& new_size) {
+  scoped_ptr<base::DictionaryValue> args(new base::DictionaryValue());
+  args->SetInteger(extensionoptions::kWidth, new_size.width());
+  args->SetInteger(extensionoptions::kHeight, new_size.height());
+  DispatchEventToEmbedder(new GuestViewBase::Event(
+      extension_options_internal::OnSizeChanged::kEventName, args.Pass()));
+}