Minimal Chrome Frame with Aura.

chrome/common/automation_messages.h

Index: chrome/common/automation_messages.h
diff --git a/chrome/common/automation_messages.h b/chrome/common/automation_messages.h
index 0f084dcdaac9651d2f02a8f9dc82f6619755a6a7..2f908f6ed809db5d8759f6fe107d5a5c630cd794 100644
--- a/chrome/common/automation_messages.h
+++ b/chrome/common/automation_messages.h
@@ -53,8 +53,10 @@ IPC_STRUCT_BEGIN(AutomationURLResponse)
   IPC_STRUCT_MEMBER(uint64, upload_size)
 IPC_STRUCT_END()
 
+#if defined(OS_WIN)
+
 IPC_STRUCT_BEGIN(ExternalTabSettings)
-  IPC_STRUCT_MEMBER(gfx::NativeWindow, parent)
+  IPC_STRUCT_MEMBER(HWND, parent)
   IPC_STRUCT_MEMBER(gfx::Rect, dimensions)
   IPC_STRUCT_MEMBER(unsigned int, style)
   IPC_STRUCT_MEMBER(bool, is_incognito)
@@ -66,6 +68,8 @@ IPC_STRUCT_BEGIN(ExternalTabSettings)
   IPC_STRUCT_MEMBER(bool, route_all_top_level_navigations)
 IPC_STRUCT_END()
 
+#endif  // defined(OS_WIN)
+
 IPC_STRUCT_BEGIN(NavigationInfo)
   IPC_STRUCT_MEMBER(int, navigation_type)
   IPC_STRUCT_MEMBER(int, relative_offset)
@@ -120,7 +124,7 @@ IPC_STRUCT_BEGIN(AttachExternalTabParams)
   IPC_STRUCT_MEMBER(std::string, profile_name)
 IPC_STRUCT_END()
 
-#if defined(OS_WIN) && !defined(USE_AURA)
+#if defined(OS_WIN)
 
 IPC_STRUCT_BEGIN(Reposition_Params)
   IPC_STRUCT_MEMBER(HWND, window)