Move GuestView IPCs into their own messages file.

extensions/common/guest_view/guest_view_messages.h

Index: extensions/common/guest_view/guest_view_messages.h
diff --git a/extensions/common/guest_view/guest_view_messages.h b/extensions/common/guest_view/guest_view_messages.h
new file mode 100644
index 0000000000000000000000000000000000000000..c9dd2e7ff32c3a823fb513b7490829ce46888a39
--- /dev/null
+++ b/extensions/common/guest_view/guest_view_messages.h
@@ -0,0 +1,57 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// IPC messages for GuestViews.
+// Multiply-included message file, hence no include guard.
+
+#include <string>
+
+#include "base/values.h"
+#include "ipc/ipc_message_macros.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/ipc/gfx_param_traits.h"
+
+#define IPC_MESSAGE_START GuestViewMsgStart
+
+// Messages sent from the browser to the renderer.
+
+// The ACK for GuestViewHostMsg_CreateMimeHandlerViewGuest.
+IPC_MESSAGE_CONTROL1(GuestViewMsg_CreateMimeHandlerViewGuestACK,
+                     int /* element_instance_id */)
+
+// Once a MimeHandlerView guest's JavaScript onload function has been called,
+// this IPC is sent to the container to notify it.
+IPC_MESSAGE_CONTROL1(GuestViewMsg_MimeHandlerViewGuestOnLoadCompleted,
+                     int /* element_instance_id */)
+
+// Once a RenderView proxy has been created for the guest in the embedder render
+// process, this IPC informs the embedder of the proxy's routing ID.
+IPC_MESSAGE_CONTROL2(GuestViewMsg_GuestAttached,
+                     int /* element_instance_id */,
+                     int /* source_routing_id */)
+
+// This IPC tells the browser process to detach the provided
+// |element_instance_id| from a GuestViewBase if it is attached to one.
+// In other words, routing of input and graphics will no longer flow through
+// the container associated with the provided ID.
+IPC_MESSAGE_CONTROL1(GuestViewMsg_GuestDetached,
+                     int /* element_instance_id*/)
+
+// Messages sent from the renderer to the browser.
+
+// Sent by the renderer to set initialization parameters of a Browser Plugin
+// that is identified by |element_instance_id|.
+IPC_MESSAGE_CONTROL4(GuestViewHostMsg_AttachGuest,
+                     int /* routing_id */,
+                     int /* element_instance_id */,
+                     int /* guest_instance_id */,
+                     base::DictionaryValue /* attach_params */)
+
+// Tells the browser to create a mime handler guest view for a plugin.
+IPC_MESSAGE_CONTROL4(GuestViewHostMsg_CreateMimeHandlerViewGuest,
+                     int /* render_frame_id */,
+                     std::string /* view_id */,
+                     int /* element_instance_id */,
+                     gfx::Size /* element_size */)
+