Move GuestView IPCs into their own messages file.

extensions/renderer/guest_view/guest_view_container.cc

Index: extensions/renderer/guest_view/guest_view_container.cc
diff --git a/extensions/renderer/guest_view/guest_view_container.cc b/extensions/renderer/guest_view/guest_view_container.cc
index a6ce3527fdc12f2345a3d9b08fa971ea5efa7ffc..636acb84811dbba3eeed089a1783bff301d563e4 100644
--- a/extensions/renderer/guest_view/guest_view_container.cc
+++ b/extensions/renderer/guest_view/guest_view_container.cc
@@ -7,8 +7,8 @@
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_frame_observer.h"
 #include "content/public/renderer/render_view.h"
-#include "extensions/common/extension_messages.h"
 #include "extensions/common/guest_view/guest_view_constants.h"
+#include "extensions/common/guest_view/guest_view_messages.h"
 
 namespace extensions {
 
@@ -50,10 +50,10 @@ GuestViewContainer::~GuestViewContainer() {}
 // static.
 bool GuestViewContainer::HandlesMessage(const IPC::Message& msg) {
   switch (msg.type()) {
-    case ExtensionMsg_CreateMimeHandlerViewGuestACK::ID:
-    case ExtensionMsg_GuestAttached::ID:
-    case ExtensionMsg_GuestDetached::ID:
-    case ExtensionMsg_MimeHandlerViewGuestOnLoadCompleted::ID:
+    case GuestViewMsg_CreateMimeHandlerViewGuestACK::ID:
+    case GuestViewMsg_GuestAttached::ID:
+    case GuestViewMsg_GuestDetached::ID:
+    case GuestViewMsg_MimeHandlerViewGuestOnLoadCompleted::ID:
       return true;
     default:
       return false;