Make several methods of TemplateUrlService const

components/search_engines/template_url_service.cc

Index: components/search_engines/template_url_service.cc
diff --git a/components/search_engines/template_url_service.cc b/components/search_engines/template_url_service.cc
index ab0ba5766fbc705618980ded02603c0ab076ef00..e5a374b7b1ce753d310c5c8d547e0e8c90bfa892 100644
--- a/components/search_engines/template_url_service.cc
+++ b/components/search_engines/template_url_service.cc
@@ -367,12 +367,12 @@ bool TemplateURLService::CanAddAutogeneratedKeyword(
 }
 
 bool TemplateURLService::IsPrepopulatedOrCreatedByPolicy(
-    const TemplateURL* t_url) {
+    const TemplateURL* t_url) const {
   return (t_url->prepopulate_id() > 0 || t_url->created_by_policy()) &&
       t_url->SupportsReplacement(search_terms_data());
 }
 
-bool TemplateURLService::ShowInDefaultList(const TemplateURL* t_url) {
+bool TemplateURLService::ShowInDefaultList(const TemplateURL* t_url) const {
   return t_url == default_search_provider_ ||
       IsPrepopulatedOrCreatedByPolicy(t_url);
 }
@@ -570,7 +570,7 @@ void TemplateURLService::ResetTemplateURL(TemplateURL* url,
     NotifyObservers();
 }
 
-bool TemplateURLService::CanMakeDefault(const TemplateURL* url) {
+bool TemplateURLService::CanMakeDefault(const TemplateURL* url) const {
   return
       ((default_search_provider_source_ == DefaultSearchManager::FROM_USER) ||
        (default_search_provider_source_ ==
@@ -621,7 +621,7 @@ bool TemplateURLService::IsSearchResultsPageFromDefaultSearchProvider(
       default_provider->IsSearchURL(url, search_terms_data());
 }
 
-bool TemplateURLService::IsExtensionControlledDefaultSearch() {
+bool TemplateURLService::IsExtensionControlledDefaultSearch() const {
   return default_search_provider_source_ ==
       DefaultSearchManager::FROM_EXTENSION;
 }
@@ -850,8 +850,9 @@ void TemplateURLService::OnWebDataServiceRequestDone(
 
 base::string16 TemplateURLService::GetKeywordShortName(
     const base::string16& keyword,
-    bool* is_omnibox_api_extension_keyword) {
-  const TemplateURL* template_url = GetTemplateURLForKeyword(keyword);
+    bool* is_omnibox_api_extension_keyword) const {
+  const TemplateURL* template_url =
+      const_cast<TemplateURLService*>(this)->GetTemplateURLForKeyword(keyword);

[Peter Kasting, 2017/04/13 22:42:52]

If you're 100% sure you'll be able to convert these functions (or add parallel
versions) and this cast will only be alive for a few days, OK.

Otherwise, I'd either avoid converting these functions in this patch, or send a
larger patch that goes ahead and converts the callees, so we don't have to add
const_cast.

 
   // TODO(sky): Once LocationBarView adds a listener to the TemplateURLService
   // to track changes to the model, this should become a DCHECK.
@@ -1629,7 +1630,7 @@ void TemplateURLService::ChangeToLoadedState() {
 }
 
 bool TemplateURLService::CanAddAutogeneratedKeywordForHost(
-    const std::string& host) {
+    const std::string& host) const {
   const TemplateURLSet* urls = provider_map_->GetURLsForHost(host);
   if (!urls)
     return true;
@@ -1640,7 +1641,7 @@ bool TemplateURLService::CanAddAutogeneratedKeywordForHost(
   return true;
 }
 
-bool TemplateURLService::CanReplace(const TemplateURL* t_url) {
+bool TemplateURLService::CanReplace(const TemplateURL* t_url) const {
   return !ShowInDefaultList(t_url) && t_url->safe_for_autoreplace();
 }
 
@@ -2230,10 +2231,14 @@ base::string16 TemplateURLService::UniquifyKeyword(const TemplateURL& turl,
   return keyword_candidate;
 }
 
-bool TemplateURLService::IsLocalTemplateURLBetter(const TemplateURL* local_turl,
-                                                  const TemplateURL* sync_turl,
-                                                  bool prefer_local_default) {
-  DCHECK(GetTemplateURLForGUID(local_turl->sync_guid()));
+bool TemplateURLService::IsLocalTemplateURLBetter(
+    const TemplateURL* local_turl,
+    const TemplateURL* sync_turl,
+    bool prefer_local_default) const {
+  const TemplateURL* templateURL =

[Peter Kasting, 2017/04/13 22:42:52]

Nit: C++ variable names are lowercase, with underscores; see
http://google.github.io/styleguide/cppguide.html#Variable_Names

+      const_cast<TemplateURLService*>(this)->GetTemplateURLForGUID(
+          local_turl->sync_guid());
+  DCHECK(templateURL);

[Peter Kasting, 2017/04/13 22:42:52]

Nit: While I'm normally fine with pulling temps out of expressions to avoid
long, multi-line things, the temp above is only used in this DCHECK, so pulling
it out basically means that when DCHECKs are off, the temp is dead code. 
Because it makes a function call, that probably means the compiler won't
eliminate it, and more critically, it might not be instantly obvious to readers
that it's only used there (although it's easier in this specific case).

So I'd weakly prefer leaving the expression inlined here, even though it's ugly.

   return local_turl->last_modified() > sync_turl->last_modified() ||
          local_turl->created_by_policy() ||
          (prefer_local_default && local_turl == GetDefaultSearchProvider());