Avoid dependency on unspecified evaluation order of parameters.

components/ntp_tiles/icon_cacher_impl.cc

 // Copyright 2016 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 "components/ntp_tiles/icon_cacher_impl.h"
 
 #include <utility>
 
 #include "components/favicon/core/favicon_service.h"
 #include "components/favicon/core/favicon_util.h"
@@ skipping 31 matching lines @@
   // For images with multiple frames, prefer one of size 128x128px.
   image_fetcher_->SetDesiredImageFrameSize(gfx::Size(128, 128));
 }
 
 IconCacherImpl::~IconCacherImpl() = default;
 
 void IconCacherImpl::StartFetch(
     PopularSites::Site site,
     const base::Closure& icon_available,
     const base::Closure& preliminary_icon_available) {
+  // From [5.2.2] of the standard, "the order of evaluation of arguments is
+  // unspecified. All side effects of argument expression evaluations take
+  // effect before the function is entered" so copy values from |site| before
+  // it is moved.

[sfiera, 2017/03/08 09:38:54]

I think "copy values from |site| before it is moved" is enough of a comment
here.

[sdefresne, 2017/03/08 18:35:35]

Done.

+  GURL site_url = site.url;
+  favicon_base::IconType icon_type = IconType(site);
   favicon::GetFaviconImageForPageURL(
-      favicon_service_, site.url, IconType(site),
+      favicon_service_, site_url, icon_type,
       base::Bind(&IconCacherImpl::OnGetFaviconImageForPageURLFinished,
                  base::Unretained(this), std::move(site), icon_available,
                  preliminary_icon_available),
       &tracker_);
 }
 
 void IconCacherImpl::OnGetFaviconImageForPageURLFinished(
     PopularSites::Site site,
     const base::Closure& icon_available,
     const base::Closure& preliminary_icon_available,
@@ skipping 34 matching lines @@
 bool IconCacherImpl::ProvideDefaultIcon(const PopularSites::Site& site) {
   if (site.default_icon_resource < 0) {
     return false;
   }
   SaveIconForSite(site, ResourceBundle::GetSharedInstance().GetNativeImageNamed(
                             site.default_icon_resource));
   return true;
 }
 
 }  // namespace ntp_tiles