[omnibox] Factor HistoryQuickProvider::DoAutocomplete()

There is a large piece of code within |HQP::DoAutocomplete()| that can
be on its own trivially. This change moves it to another method, and
should not change behavior. This is to facilitate a downstream change.

Bug: 
Change-Id: Ifdbbac697aee1efd0f42068f2e0825bb176a8076
Reviewed-on: https://chromium-review.googlesource.com/747064
Commit-Queue: Kevin Bailey <krb@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513013}

components/omnibox/browser/history_quick_provider.cc

@@ -74,6 +74,24 @@ void HistoryQuickProvider::DoAutocomplete() {
   if (matches.empty())
     return;
 
+  // Loop over every result and add it to matches_.  In the process,
+  // guarantee that scores are decreasing.  |max_match_score| keeps
+  // track of the highest score we can assign to any later results we
+  // see.
+  int max_match_score = FindMaxMatchScore(matches);
+  for (ScoredHistoryMatches::const_iterator match_iter = matches.begin();
+       match_iter != matches.end(); ++match_iter) {
+    const ScoredHistoryMatch& history_match(*match_iter);
+    // Set max_match_score to the score we'll assign this result.
+    max_match_score = std::min(max_match_score, history_match.raw_score);
+    matches_.push_back(QuickMatchToACMatch(history_match, max_match_score));
+    // Mark this max_match_score as being used.
+    max_match_score--;
+  }
+}
+
+int HistoryQuickProvider::FindMaxMatchScore(
+    const ScoredHistoryMatches& matches) {
   // Figure out if HistoryURL provider has a URL-what-you-typed match
   // that ought to go first and what its score will be.
   bool will_have_url_what_you_typed_match_first = false;
@@ -160,30 +178,17 @@ void HistoryQuickProvider::DoAutocomplete() {
       }
     }
   }
-
-  // Loop over every result and add it to matches_.  In the process,
-  // guarantee that scores are decreasing.  |max_match_score| keeps
-  // track of the highest score we can assign to any later results we
-  // see.  Also, reduce |max_match_score| if we think there will be
-  // a URL-what-you-typed match.  (We want URL-what-you-typed matches for
-  // visited URLs to beat out any longer URLs, no matter how frequently
-  // they're visited.)  The strength of this reduction depends on the
-  // likely score for the URL-what-you-typed result.
-
+  // Return a |max_match_score| that is the raw score for the first match, but
+  // reduce it if we think there will be a URL-what-you-typed match.  (We want
+  // URL-what-you-typed matches for visited URLs to beat out any longer URLs, no
+  // matter how frequently they're visited.)  The strength of this reduction
+  // depends on the likely score for the URL-what-you-typed result.
   int max_match_score = matches.begin()->raw_score;
   if (will_have_url_what_you_typed_match_first) {
     max_match_score = std::min(max_match_score,
         url_what_you_typed_match_score - 1);
   }
-  for (ScoredHistoryMatches::const_iterator match_iter = matches.begin();
-       match_iter != matches.end(); ++match_iter) {
-    const ScoredHistoryMatch& history_match(*match_iter);
-    // Set max_match_score to the score we'll assign this result.
-    max_match_score = std::min(max_match_score, history_match.raw_score);
-    matches_.push_back(QuickMatchToACMatch(history_match, max_match_score));
-    // Mark this max_match_score as being used.
-    max_match_score--;
-  }
+  return max_match_score;
 }
 
 AutocompleteMatch HistoryQuickProvider::QuickMatchToACMatch(

components/omnibox/browser/history_quick_provider.h

@@ -47,6 +47,10 @@ class HistoryQuickProvider : public HistoryProvider {
   // Performs the autocomplete matching and scoring.
   void DoAutocomplete();
 
+  // Calculates the initial max match score for applying to matches, lowering
+  // it if we believe that there will be a URL-what-you-typed match.
+  int FindMaxMatchScore(const ScoredHistoryMatches& matches);
+
   // Creates an AutocompleteMatch from |history_match|, assigning it
   // the score |score|.
   AutocompleteMatch QuickMatchToACMatch(const ScoredHistoryMatch& history_match,

components/omnibox/browser/history_url_provider.cc

@@ -488,10 +488,10 @@ void HistoryURLProvider::Start(const AutocompleteInput& input,
       fixed_up_input, fixed_up_input.canonicalized_url(), trim_http));
   what_you_typed_match.relevance = CalculateRelevance(WHAT_YOU_TYPED, 0);
 
-  // Add the WYT match as a fallback in case we can't get the history service or
-  // URL DB; otherwise, we'll replace this match lower down.  Don't do this for
-  // queries, though -- while we can sometimes mark up a match for them, it's
-  // not what the user wants, and just adds noise.
+  // Add the what-you-typed match as a fallback in case we can't get the history
+  // service or URL DB; otherwise, we'll replace this match lower down.  Don't
+  // do this for queries, though -- while we can sometimes mark up a match for
+  // them, it's not what the user wants, and just adds noise.
   if (fixed_up_input.type() != metrics::OmniboxInputType::QUERY)
     matches_.push_back(what_you_typed_match);
 
@@ -799,7 +799,8 @@ void HistoryURLProvider::DoAutocomplete(history::HistoryBackend* backend,
     //     what-you-typed match to be added in this case.  See comments in
     //     PromoteMatchesIfNecessary().
     //   * Otherwise, we should have some sort of QUERY or UNKNOWN input that
-    //     the SearchProvider will provide a defaultable WYT match for.
+    //     the SearchProvider will provide a defaultable what-you-typed match
+    //     for.
     params->promote_type = HistoryURLProviderParams::FRONT_HISTORY_MATCH;
   } else {
     // Failed to promote any URLs.  Use the What You Typed match, if we have it.

components/omnibox/browser/history_url_provider_unittest.cc

@@ -610,8 +610,8 @@ TEST_F(HistoryURLProviderTest, CullRedirects) {
 }
 
 TEST_F(HistoryURLProviderTestNoSearchProvider, WhatYouTypedNoSearchProvider) {
-  // When no search provider is available, make sure we provide WYT matches
-  // for text that could be a URL.
+  // When no search provider is available, make sure we provide what-you-typed
+  // matches for text that could be a URL.
 
   const UrlAndLegalDefault results_1[] = {
     { "http://wytmatch/", true }