Remove page IDs from three WebContentsObserver APIs that don't need it.

content/common/frame_messages.h

 // Copyright 2013 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 interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include "content/common/content_export.h"
 #include "content/common/content_param_traits.h"
 #include "content/common/frame_message_enums.h"
@@ skipping 412 matching lines @@
 
 // Requests that the given URL be opened in the specified manner.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_OpenURL, FrameHostMsg_OpenURL_Params)
 
 // Notifies the browser that a frame finished loading.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_DidFinishLoad,
                     GURL /* validated_url */)
 
 // Sent when after the onload handler has been invoked for the document
 // in this frame. Sent for top-level frames.
-IPC_MESSAGE_ROUTED1(FrameHostMsg_DocumentOnLoadCompleted,
-                    int32 /* page_id */)
+IPC_MESSAGE_ROUTED0(FrameHostMsg_DocumentOnLoadCompleted)
 
 // Notifies that the initial empty document of a view has been accessed.
 // After this, it is no longer safe to show a pending navigation's URL without
 // making a URL spoof possible.
 IPC_MESSAGE_ROUTED0(FrameHostMsg_DidAccessInitialDocument)
 
 // Sent when the frame sets its opener to null, disowning it for the lifetime of
 // the window. Sent for top-level frames.
 IPC_MESSAGE_ROUTED0(FrameHostMsg_DidDisownOpener)
 
@@ skipping 138 matching lines @@
                     SkColor /* color */)
 
 // Notifies the browser that media has started/stopped playing.
 IPC_MESSAGE_ROUTED3(FrameHostMsg_MediaPlayingNotification,
                     int64 /* player_cookie, distinguishes instances */,
                     bool /* has_video */,
                     bool /* has_audio */)
 
 IPC_MESSAGE_ROUTED1(FrameHostMsg_MediaPausedNotification,
                     int64 /* player_cookie, distinguishes instances */)