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

chrome/browser/extensions/favicon_downloader.cc

 // 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.
 
 #include "chrome/browser/extensions/favicon_downloader.h"
 
 #include "base/bind.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/favicon_url.h"
@@ skipping 94 matching lines @@
 void FaviconDownloader::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   // Clear all pending requests.
   in_progress_requests_.clear();
   favicon_map_.clear();
   callback_.Run(false, favicon_map_);
 }
 
 void FaviconDownloader::DidUpdateFaviconURL(
-    int32 page_id,
     const std::vector<content::FaviconURL>& candidates) {
   // Only consider the first candidates we are given. This prevents pages that
   // change their favicon from spamming us.
   if (got_favicon_urls_)
     return;
 
   got_favicon_urls_ = true;
   FetchIcons(candidates);
 }