Eliminate |url_ref_| and use url_refs_.back().

BUG=789424
TEST=none

Change-Id: If6f9a889c5b67684c7157c451ccfc3e459c9e50d
Reviewed-on: https://chromium-review.googlesource.com/799850Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520842}

components/search_engines/template_url.cc

@@ -1155,7 +1155,6 @@ TemplateURL::AssociatedExtensionInfo::~AssociatedExtensionInfo() {
 
 TemplateURL::TemplateURL(const TemplateURLData& data, Type type)
     : data_(data),
-      url_ref_(nullptr),
       suggestions_url_ref_(this, TemplateURLRef::SUGGEST),
       image_url_ref_(this, TemplateURLRef::IMAGE),
       new_tab_url_ref_(this, TemplateURLRef::NEW_TAB),
@@ -1247,7 +1246,7 @@ base::string16 TemplateURL::AdjustedShortNameForLocaleDirection() const {
 
 bool TemplateURL::SupportsReplacement(
     const SearchTermsData& search_terms_data) const {
-  return url_ref_->SupportsReplacement(search_terms_data);
+  return url_ref().SupportsReplacement(search_terms_data);
 }
 
 bool TemplateURL::HasGoogleBaseURLs(
@@ -1264,10 +1263,9 @@ bool TemplateURL::HasGoogleBaseURLs(
 
 bool TemplateURL::IsGoogleSearchURLWithReplaceableKeyword(
     const SearchTermsData& search_terms_data) const {
-  return (type_ == NORMAL) &&
-      url_ref_->HasGoogleBaseURLs(search_terms_data) &&
-      google_util::IsGoogleHostname(base::UTF16ToUTF8(data_.keyword()),
-                                    google_util::DISALLOW_SUBDOMAIN);
+  return (type_ == NORMAL) && url_ref().HasGoogleBaseURLs(search_terms_data) &&
+         google_util::IsGoogleHostname(base::UTF16ToUTF8(data_.keyword()),
+                                       google_util::DISALLOW_SUBDOMAIN);
 }
 
 bool TemplateURL::HasSameKeywordAs(
@@ -1386,10 +1384,10 @@ void TemplateURL::EncodeSearchTerms(
 
 GURL TemplateURL::GenerateSearchURL(
     const SearchTermsData& search_terms_data) const {
-  if (!url_ref_->IsValid(search_terms_data))
+  if (!url_ref().IsValid(search_terms_data))
     return GURL();
 
-  if (!url_ref_->SupportsReplacement(search_terms_data))
+  if (!url_ref().SupportsReplacement(search_terms_data))
     return GURL(url());
 
   // Use something obscure for the search terms argument so that in the rare
@@ -1397,7 +1395,7 @@ GURL TemplateURL::GenerateSearchURL(
   // same url.
   // TODO(jnd): Add additional parameters to get post data when the search URL
   // has post parameters.
-  return GURL(url_ref_->ReplaceSearchTerms(
+  return GURL(url_ref().ReplaceSearchTerms(
       TemplateURLRef::SearchTermsArgs(
           base::ASCIIToUTF16("blah.blah.blah.blah.blah")),
       search_terms_data, nullptr));
@@ -1416,7 +1414,7 @@ void TemplateURL::CopyFrom(const TemplateURL& other) {
 void TemplateURL::SetURL(const std::string& url) {
   data_.SetURL(url);
   engine_type_ = SEARCH_ENGINE_UNKNOWN;
-  url_ref_->InvalidateCachedValues();
+  url_ref().InvalidateCachedValues();
 }
 
 void TemplateURL::SetPrepopulateId(int id) {
@@ -1455,14 +1453,11 @@ void TemplateURL::ResizeURLRefVector() {
   if (url_refs_.size() == new_size)
     return;
 
-  // See comment on TemplateURL::ExtractSearchTermsFromURL() for understanding
-  // the order of TemplateURLRefs in the |url_refs_| vector.
   url_refs_.clear();
   url_refs_.reserve(new_size);
   for (size_t i = 0; i != data_.alternate_urls.size(); ++i)
     url_refs_.emplace_back(this, i);
   url_refs_.emplace_back(this, TemplateURLRef::SEARCH);
-  url_ref_ = &url_refs_.back();
 }
 
 bool TemplateURL::FindSearchTermsInURL(

components/search_engines/template_url.h

@@ -578,7 +578,7 @@ class TemplateURL {
   const std::string& sync_guid() const { return data_.sync_guid; }
 
   const std::vector<TemplateURLRef>& url_refs() const { return url_refs_; }
-  const TemplateURLRef& url_ref() const { return *url_ref_; }
+  const TemplateURLRef& url_ref() const { return url_refs_.back(); }
   const TemplateURLRef& suggestions_url_ref() const {
     return suggestions_url_ref_;
   }
@@ -624,13 +624,8 @@ class TemplateURL {
 
   // Use the alternate URLs and the search URL to match the provided |url|
   // and extract |search_terms| from it. Returns false and an empty
-  // |search_terms| if no search terms can be matched. The order in which the
-  // alternate URLs are listed dictates their priority, the URL at index 0 is
-  // treated as the highest priority and the primary search URL is treated as
-  // the lowest priority. For example, if a TemplateURL has alternate URL
-  // "http://foo/#q={searchTerms}" and search URL "http://foo/?q={searchTerms}",
-  // and the URL to be decoded is "http://foo/?q=a#q=b", the alternate URL will
-  // match first and the decoded search term will be "b".
+  // |search_terms| if no search terms can be matched. The URLs are matched in
+  // the order listed in |url_refs_| (see comment there).
   bool ExtractSearchTermsFromURL(const GURL& url,
                                  const SearchTermsData& search_terms_data,
                                  base::string16* search_terms) const;
@@ -688,7 +683,8 @@ class TemplateURL {
   void ResetKeywordIfNecessary(const SearchTermsData& search_terms_data,
                                bool force);
 
-  // Resizes the |url_refs_| vector and sets |url_ref_| according to |data_|.
+  // Resizes the |url_refs_| vector, which always holds the search URL as the
+  // last item.
   void ResizeURLRefVector();
 
   // Uses the alternate URLs and the search URL to match the provided |url|
@@ -704,14 +700,15 @@ class TemplateURL {
   TemplateURLData data_;
 
   // Contains TemplateURLRefs corresponding to the alternate URLs and the search
-  // URL. This vector must not be resized except by ResizeURLRefVector() to keep
-  // the |url_ref_| pointer correct.
+  // URL, in priority order: the URL at index 0 is treated as the highest
+  // priority and the primary search URL is treated as the lowest priority.  For
+  // example, if a TemplateURL has alternate URL "http://foo/#q={searchTerms}"
+  // and search URL "http://foo/?q={searchTerms}", and the URL to be decoded is
+  // "http://foo/?q=a#q=b", the alternate URL will match first and the decoded
+  // search term will be "b".  Note that since every TemplateURLRef has a
+  // primary search URL, this vector is never empty.
   std::vector<TemplateURLRef> url_refs_;
 
-  // Points to the TemplateURLRef in |url_refs_| which corresponds to the search
-  // URL.
-  TemplateURLRef* url_ref_;
-
   TemplateURLRef suggestions_url_ref_;
   TemplateURLRef image_url_ref_;
   TemplateURLRef new_tab_url_ref_;